Document zdQB4ydVEBaxNYR8mVrD3MRqB
2.0
INTERNATIONAL TECHNOLOGY ROADMAP
FOR
SEMICONDUCTORS 2.0
2015 EDITION
YIELD ENHANCEMENT
THE ITRS IS DEVISED AND INTENDED FOR TECHNOLOGY ASSESSMENT ONLY AND IS WITHOUT REGARD TO ANY COMMERCIAL CONSIDERATIONS PERTAINING TO INDIVIDUAL PRODUCTS OR EQUIPMENT.
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Table of Contents
0Yield Enhancement ..............................................................................................................241
11. Scope ..................................................................................................................................... 251 22. Difficult Challenges................................................................................................................. 263
32.1. Wafer Environmental Contamination Control................................................................................ 275 42.2. Characterization, Inspection and Analysis .................................................................................. 2850 53. Potential Solutions ............................................................................................................... 2950 63.1. Wafer Environmental Contamination Control.............................................................................. 3050 73.2. Characterization, Inspection and Analysis .................................................................................. 3155 84. Yield Enhancement Supplemental Links.............................................................................. 3256 95. References ........................................................................................................................... 3356
List of Figures
10Figure YE1 Yield Enhancement Scope ................................................................................................... 341 11Figure YE2 General Test Methodology for Ultrapure Water ................................................................. 3543 12Figure YE3 Wafer Environment and Reticle Environment Contamination Measurement and Control Potential Solutions (last updated in 2013)..................................................................................................... 3652 13Figure YE4 Wafer Environmental Contamination Control Potential Solutions-UPW ............................ 3753 14Figure YE5 Wafer Environmental Contamination Control Potential Solutions-Liquid Chemicals ......... 3854 15Figure YE6 Characterization, Inspection and Analysis Potential Solutions (last updated in 2011) ...... 3955
List of Tables
16Table YE1 Definitions for the Different Interface Points ........................................................... 402 17Table YE2 Yield Enhancement Difficult Challenges................................................................. 414 18Table YE3 Technology Requirements for Wafer Environmental Contamination Control ......... 425 19Table YE4 AMC Monitoring Methods ..................................................................................... 4329 20Table YE4a Supporting Table for On-line Methods (see Excel for more readable version)..... 4436
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 1
YIELD ENHANCEMENT
1. SCOPE
Yield in most industries has been defined as the number of products that can be sold divided by the number of products that can be potentially made. In the semiconductor industry, yield is represented by the functionality and reliability of integrated circuits produced on the wafer surfaces. During the manufacturing of integrated circuits yield loss is caused for example by defects, faults, process variations, and design. The relationship of defects and yield, and an appropriate yield to defect correlation, is critical for yield enhancement.
The previous scope of the Yield Enhancement group, which was More Moore driven front end processing, will be extended towards More Moore and More Than More yield considerations. The road mapping focus will move from a technology orientation to a product/application orientation. Thereby, all Yield Enhancement tables will be considerably reworked for ITRS 2.0. The Yield Enhancement section will display the current and future requirements for high yielding manufacturing of Moore More as well as Moore than Moore products separated in "critical process groups" including back-end processes, e. g. packaging. Consequently, an inclusion of material specifications for Si, SiC, GaN etc. will be considered.
Airborne molecular contamination (AMC), packaging, liquid chemicals and ultra-pure water were identified as main focus topics for the next period. Electrical characterization methods, Big Data and modeling will become more and more important for yield learning and yield prediction. Here Yield Enhancement greatly benefits from the big data activities within the Factory Integration iTWG. Regarding AMC, liquid chemicals and ultra-pure water a close link to Environmental Safety and Health iTWG is already indicated.
As a result of the increased synergy of some of the Yield Enhancement topics with Factory Integration (e.g., big data, yield prediction and yield enhancement), the Yield Enhancement roadmap is now included in the FI Focus Area chapter. Due to the changed focus of the Yield Enhancement group several cross TWG activities are envisaged, connections with More Moore (MM), Heterogeneous Integration (HI) and Heterogeneous Components (HC) are necessary.
overlay
ESD Damage
Interconnects
Via
Metal 1 particle
short
particle
Metal 2
open
crack layer thickness
p+ n
n-well
n+ p p contamination
COP
p-well
interfaces:
roughness,
state density, charges
Si crystal: stacking faults, contamination, stress, COP
Figure YE1 Yield Enhancement Scope In the manufacture of integrated circuits yield loss is related to a variety of sources. During processes such as implantation, etching, deposition, planarization, cleaning, lithography, etc. failures responsible for yield loss occur. Several examples of contaminations and mechanisms responsible for yield loss are listed in the following: a) airborne molecular contamination (AMC) or particles of organic or inorganic matter caused by the environment or by the tools; b) process induced defects as scratches, cracks, and particles, overlay faults, and stress; c) process variations resulting, e.g., in differing doping profiles or layer thicknesses; d) the
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
2 Yield Enhancement
deviation from design, due to pattern transfer from the mask to the wafer, results in deviations and variations of layout and critical dimensions; and e) diffusion of atoms through layers and in the semiconductor bulk material.
The determination of defects and yield, and an appropriate yield to defect correlation are essential for yield enhancement. This correlation is of major importance, because not all defects change device properties or cause failure of devices or integrated circuits. Therefore, the yield enhancement chapter addresses not only the identification of tolerable contamination limits for processes and media, but also the tolerable budgets for particulate contamination of tools. The specification of tools for defect detection and classification of defects for root cause analysis addresses the technology requirements for detection and characterization of faults and failures.
The YE section has two focus topics: "Wafer Environment Contamination Control" and "Characterization, Inspection and Analysis." These two topics crosscut front end process technology, interconnect processes, lithography, metrology, design, process integration, test, and facility infrastructures.
Wafer Environment Contamination Control--Order-of-magnitude improvements in process critical fluid and gas impurity levels are not considered to be necessary in the foreseeable future. New materials and their precursors, however, introduce challenges that require continuous study. Clarification of potential contamination from point-of-supply to point-of-process will define control systems necessary for delivered purity. There are several locations in the pathway from the original delivery package, i.e., the Point of Supply (POS) of a liquid or gas to the location where that material contacts the wafer, i.e., the Point of Process (POP), for ascertaining purity. This has led to a considerable amount of confusion and ambiguity in discussing the quality of process fluids, including the data found in Table YE3. Table YE1 summarizes the major fluid handling and/or measurement nodes found along the typical systems supplying process fluid. This table is an effort to create a common language for the discussion of attributes and requirements at these different node points. Further information regarding pathway nodes can be found in the supplementary materials and references, such as the Semiconductor Equipment and Materials International (SEMI) Standards.
Table YE1 Definitions for the Different Interface Points
POS
POD
POC
POE
POU
POP
Delivery Point of Gas/Chemical Supplier
Outlet of Central Facility System
Submain or VMB/VMP Take off Valve
Entry to Equipment or Sub Equipment
Entry to the Process Chamber
Contact with Wafer
Interfaces
SEMI Standards Focus Area
ITRS Factory Integration Facilities Group Focus Area
ITRS Factory Integration Equipment Group Focus Area
ITRS Front End Processes, Lithography,
Interconnect TWG Focus Area
Ultrapure water
Raw water
Outlet of final filtration in UPW plant
Outlet of submain take off valve
Inlet of wet bench or subequipment
Inlet of wet bench bath, spray nozzle, or connection point to piping, which is also used for other chemicals
Wafer in production
Process chemicals
Chemical drum/tote/bulk supply
Outlet of final filtration of chemical distribution unit
Outlet of VMB valve
Inlet of wet bench or intermediate tank
Inlet of wet bench bath or spray nozzle
Wafer in production
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 3
Specialty gases
Gas cylinder or bulk specialty gas systems
Outlet of final filtration of gas cabinet
Outlet of VMB valve
Inlet of equipment
Inlet of chamber (outlet of MFC)
Wafer in production
Bulk gases
Bulk gas delivered on site or gas generator
Outlet of final filtration/purification
Outlet of submain take off valve or VMB valve
Inlet of equipment/ subequipment
Inlet of chamber (outlet of MFC)
Wafer in production
Cleanroom and AMC
Outside air
Outlet of make-up air handling unit
Outlet of filters in cleanroom ceiling
Inlet to minienvironment or sub equipment for AMC, outlet of the tool filter for particles
Gas/air in vicinity to wafer/substrate
Wafer/substrate in production (AMC/ SMC)
POD--point of delivery POC--point of connection POE--point of entry POP--point of process POU--point of use VMB-- valve manifold box
VMP--valve manifold post
UPW--ultra pure water
MFC--mass flow controller
AMC--airborne molecular contamination
SMC--surface molecular contamination
Characterization, Inspection and Analysis--Physical device dimensions and corresponding defect dimensions continue shrinking, posing new challenges to detection as well as tolerable contamination. The wafer edges and backside were identified to show significant impact on yield as well as process variations and design. Development of defect detection, defect review, and classification technologies showing highest sensitivity at high throughput is crucial for cost efficient manufacturing. Furthermore for efficient manufacturing the monitoring of contamination in the environment and on the wafer surface requires appropriate analytic capabilities. Automated, intelligent analysis and reduction algorithms, which correlate facility, design, process, electrical and virtual metrology results and their correlation to yield, test and work-in-progress data, will have to be developed to enhance root cause analysis and therefore enable rapid yield learning.
2. DIFFICULT CHALLENGES
The difficult challenges for the Yield Enhancement chapter are summarized in Table YE2. Currently, the most important key challenge will be the detection of multiple killer defects and the signal-to-noise ratio. It is a challenge to detect multiple killer defects and to differentiate them simultaneously at high capture rates, low cost of ownership and high throughput. Furthermore, it is difficult to identify yield relevant defects under a vast amount of nuisance and false defects. As a challenge with second priority the requirement for 3D inspection was identified. This necessitates for inspection tools the capability to inspect high aspect ratios but also to detect non-visuals such as voids, embedded defects, and sub-surface defects is crucial. The demand for high-speed and cost-effective inspection tools remains, especially in the area of 3D inspection as the importance of 3D defect types increases. In 2011 and also with the change of the scope of the subchapter to Characterization, Inspection and Analysis a new key challenge was identified: Detection of organic contamination on surfaces - The detection and speciation of non-volatile organics on surfaces is currently not possible in the fab. There is no laboratory or fab scale instrumentation available or implemented.
Other topics challenging the Yield Enhancement community are prioritized as follows in the near term:
Process Stability versus Absolute Contamination Level
Wafer Edge, Backside and Bevel Monitoring and Contamination Control
Development of sub 10 nm water and chemical liquid particle counter
Correlation Yield and Contamination Levels
In 2011 the identification of Non-Visual Defects and Process Variations was set to the most important key challenge in the future. Data, test structures, and methods are needed for correlating process fluid
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
4 Yield Enhancement
contamination types and levels to yield and to determine the required control limits. The issues for this challenge are to define the relative importance of different contaminants to wafer yield, a standard test for yield/parametric effect, and a maximum process variation (control limits). The fundamental challenge is to understand the correlation between impurity concentration in key process steps and device yield, reliability, and performance. This correlation will determine whether further increases in contamination limits are truly required. The challenge increases in complexity as the range of process materials widens and selection of the most sensitive processes for study will be required for meaningful progress.
Furthermore, in the long term the following key challenges were identified:
In-line Defect Characterization and Analysis Next generation lithography
Table YE2 Yield Enhancement Difficult Challenges
Difficult Challenges 2015-2020
It is a challenge to detect multiple killer defect types and to differentiate them simultaneously at high capture rates, low cost of ownership and high throughput. Furthermore, it is a dare to identify yield relevant defects under a vast amount of nuisance and false defects.
Summary of Issues
Existing techniques trade-off throughput for sensitivity, but at expected defect levels, both throughput and sensitivity are necessary for statistical validity.
Reduction of inspection costs and increase of throughput is crucial in view of CoO.
Detection of line roughness due to process variation.
Electrical and physical failure analysis for killer defects at high capture rate, high throughput and high precision.
Reduction of background noise from detection units and samples to improve the sensitivity of systems.
Improvement of signal to noise ratio to delineate defect from process variation.
Where does process variation stop and defect start?
Process Stability vs. Absolute Contamination Level - This includes the correlation to yield test structures, methods and data that are needed for correlating defects caused by wafer environment and handling to yield. This requires determination of control limits for gases, chemicals, air, precursors, ultrapure water and substrate surface cleanliness.
Systematic Mechanisms Limited Yield (SMLY), resulting from unrecognized models hidden in the chip, should be efficiently identified and tackled through logic diagnosis capability designed into products and systematically incorporated in the test flow. It is required to manage the above models at both the design and the manufacturing stage. Potential issues can arise due to:
a) Accommodation of different Automatic Test Pattern Generation (ATPG) flows.
b) Automatic Test Equipment (ATE) architecture which might lead to significant test time increase when logging the numbers of vectors necessary for the logic diagnosis to converge.
c) Logic diagnosis runs time per die.
d) Statistical methodology to analyze results of logic diagnosis for denoising influence of random defects and building a layoutdependent systematic yield model.
Test pattern generation has to take into account process versus layout marginalities (hotspots) which might cause systematic loss, and has to improve their coverage.
Methodology for employment and correlation of fluid/gas types to yield of a standard test structure/product.
Relative importance of different contaminants to wafer yield.
Define a standard test for yield/parametric effect.
A possible work around is the use of NEXAF at a synchrotron radiation facility.
Difficult Challenges Beyond 2020
Summary of Issues
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 5
Table YE2 Yield Enhancement Difficult Challenges
Difficult Challenges 2015-2020
Next Generation Inspection As bright field detection in the farfield loses its ability to discriminate defects of interest, it has become necessary to explore new alternative technologies that can meet inspection requirements beyond 13 nm node. Several techniques should be given consideration as potential candidates for inspection: high speed scanning probe microscopy, near-field scanning optical microscopy, interferometry, scanning capacitance microscopy and e-beam. This assessment should include each technique's ultimate resolution, throughput and potential interactions with samples (contamination, or degree of mechanical damage) as key success criteria.
In-line Defect Characterization and Analysis - Based on the need to work on smaller defect sizes and feature characterization, alternatives to optical systems and Energy Dispersive X-ray Spectroscopy systems are required for high throughput in-line characterization and analysis for defects smaller than feature sizes. The data volume to be analyzed is drastically increasing, therefore demanding for new methods for data interpretation and to ensure quality. [1]
Next generation lithography - Manufacturing faces several choices of lithography technologies in the long term, which all pose different challenges with regard to yield enhancement, defect and contamination control.
Summary of Issues
Several techniques should be given consideration as potential candidates for inspection: high speed scanning probe microscopy, near-field scanning optical microscopy, interferometry, scanning capacitance microscopy and ebeam. This path finding exercise needs to assess each technique's ultimate resolution, throughput and potential interactions with samples (contamination, or degree of mechanical damage) as key success criteria.
Data volume + quality: strong increase of data volume due to miniaturization
The probe for sampling should show minimum impact as surface damage or destruction from SEM image resolution.
It will be recommended to supply information on chemical state and bonding especially of organics.
Small volume technique adapted to the scales of technology generations. Capability to distinguish between the particle and the substrate signal.
2.1. WAFER ENVIRONMENTAL CONTAMINATION CONTROL
Wafer environmental contamination control requirements are categorized by manufacturing materials or environment, as shown in Table YE3.
Table YE3 Technology Requirements for Wafer Environmental Contamination Control
Year of
Production
DRAM Pitch (nm) (contacted) Critical particle size (nm) based on 50% of DRAM 1/2 Pitch (nm (contacted) [1]
Wafer Environment Control such as Cleanroom, SMIF POD, FOUP, etc....not necessarily the cleanroom itself but wafer environment. Number of particles (/m3) [1] [2]
Airborne Molecular Contaminants in Gas Phase (pptV, V for Volume)) [3, 7, 12,13,14,15,33].
Lithography: Point of entry ( POE) to exposure tool [23] Total Inorganic Acids
Total Organic Acids [30] Total Bases
PGMEA, Ethyl Lactate Volatile Organics (w/
2015 24 12
ISO CL1
5,000 2000 20,000 5,000 26,000
2016 22 11
ISO CL1
5,000 2000 20,000 5,000 26,000
2017 20 10
ISO CL1
5,000 2000 20,000 5,000 26,000
2018 18 9
ISO CL1
5,000 2000 20,000 5,000 26,000
2019 17 8.5
ISO CL1
5,000 tbd 50,000 5,000 26,000
2020 15 7.5
ISO CL1
5,000 tbd 50,000 5,000 26,000
2021 14 7
ISO CL1
5,000 tbd 50,000 5,000 26,000
2022 13 6.5
ISO CL1
5,000 tbd 50,000 5,000 26,000
2023 12 6
ISO CL1
5,000 tbd 50,000 5,000 26,000
2024 11 5.5
ISO CL1
5,000 tbd 50,000 5,000 26,000
2025 10 5
ISO CL1
5,000 tbd 50,000 5,000 26,000
2026 9.2 4.6
ISO CL1
5,000 tbd 50,000 5,000 26,000
2027 8.4 4.2
ISO CL1
5,000 tbd 50,000 5,000 26,000
2028 7.7 3.9
ISO CL1
5,000 tbd 50,000 5,000 26,000
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
6 Yield Enhancement
GCMS retention times benzene, calibrated to hexadecane) [31] Refractory compounds (organics containing for example S, P, Si) [40] [43]
Lithography: Point
of entry (POE) to
track & inspection
tools; temporary
reticle pod storage Total Inorganic Acids
Total Organic Acids [30] Total Bases
PGMEA, Ethyl Lactate Condensable organics (definition to SEMI F21-95, bp 150 C) Refractory compounds (organics containing for example S, P, Si)
2000
2,000 2,000 2,000 5,000 1,000 tbd
<200 <200 <200 < 100 tbd
<200 <200 <200 < 100 tbd
2000
2,000 2,000 2,000 5,000 1,000
tbd
<200 <200 <200 < 100 tbd
2000
2,000 2,000 2,000 5,000 1,000
tbd
<200 <200 <200 < 100 tbd
2000
2,000 2,000 2,000 5,000 1,000
tbd
<200 <200 <200 < 100 tbd
2000
2,000 2,000 2,000 5,000 1,000
tbd
<200 <200 <200 < 100 tbd
2000
2,000 2,000 2,000 5,000 1,000
tbd
<200 <200 <200 < 100 tbd
2000
2,000 2,000 2,000 5,000 1,000
tbd
<200 <200 <200 < 100 tbd
2000
2,000 2,000 2,000 5,000 1,000
tbd
<200 <200 <200 < 100 tbd
2000
2,000 2,000 2,000 5,000 1,000
tbd
<200 <200 <200 < 100 tbd
2000
2,000 2,000 2,000 5,000 1,000
tbd
<200 <200 <200 < 100 tbd
2000
2,000 2,000 2,000 5,000 1,000
tbd
<200 <200 <200 < 100 tbd
2000
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tbd
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2000
2,000 2,000 2,000 5,000 1,000
tbd
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2000
2,000 2,000 2,000 5,000 1,000 tbd
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THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 7
Total Inorganic Acids
Total Bases
Total Organic Acids [30] Total other corrosive species [32] H2S
Total sulphur compounds
Exposed Copper Wafer Environment (FOUP inside) Total Inorganic Acids
HCl
HF
HBr
HNOx
Total Organic Acids [30] Total bases
Total other corrosive species [32] H2S
Total sulphur compounds Moisture (ppb)
Exposed Aluminum Wafer Environment (FOUP inside) Total Inorganic Acids
HCl
HF
HBr
HNOx
Total Organic Acids [30] Total other corrosive species [32]
Critical areas (Litho, Metrology) Temperature range in +/-K at POE [37] Maximum short term temperature variation at POE in +/-K/5 min [37] Maximum long term temperature variation in +/-K/hour at POE [37] Humidity range in +/% relative humdity r.H. at POE [37] Humidity range in +/% relative humidity r.H. at POE [37] Maximum short term humidity variation in +/-r.H./5 min at POE [37]
Non-critical areas (others than Litho, Metrology) Temperature range on +/-K at POE [37] Humidity range in +/% relative humdity r.H. at POE [37] Humidity range in +/% relative humidity r.H. at POE [37]
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THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
8 Yield Enhancement
Ultrapure Water [29]
Total organic carbon
<1
(ppb) [22] for
immersion
photolithography,
POE
Critical Organics as
<1
C (ppb) [22], POE
Non-critical organics
<3
as C (ppb) [22], POE
Reactive silica (ppb)
<0.3
as SiO2 [18], POC
Total silica (ppb) as
<0.3
SiO2 [18], POC
Number of particles
1000
>critical particle size
(see above) (#/L)
[26], POE
Number of particles
100
for EUV mask
production >critical
particle size (see
above) (#/L) [26.3],
POE
Dissolved oxygen
<10
(ppb) (contaminant
based) [16] POE
Dissolved nitrogen
8-18
(ppm) [10] POE
Hydrogen Peroxide
TBD
(ppb) [42] POD
Metals (ppt each)
<10
(As, Ba, Cd, Mn, Pb,
Sn, Sb, V) [39], POP
Critical metals (ppt,
<1.0
each) (Al, Ca, Cr, Cu,
Fe, K, Li, Mg, Na, Ni,
Ti, Zn) [39], POP
Other critical ions
<50
(ppt each) [24], POP
Phosphate as HPO4
<20
(ppt), POP
Boron (ppt) [24],
<50
POP
Temperature stability
1
(K) [38], POE
Temperature
<0.1
gradient in K/10
minutes [38] for
immersion
photolithography,
POE [38]
Liquid Chemicals
All cleaning
0.19
chemistries (aqueous
and solvent): number
of particles/ml
>0.065um
[1,calculation based
on exponent of 3.0]
[11]
All cleaning
0.81
chemistries (aqueous
and solvent): number
of particles/ml
>0.040um
[1,calculation based
on exponent of 3.0]
[11]
All cleaning
1.9
chemistries (aqueous
and solvent): number
of particles/ml
>0.030um
[1,calculation based
on exponent of 3.0]
[11]
<1
<1 <3 <0.3 <0.3 1000 100
<10 8-18 TBD <10 <1.0 <50 <20 <50 1 <0.1
0.15
0.62
1.5
<1
<1 <3 <0.3 <0.3 1000 100
<10 8-18 TBD <10 <1.0 <50 <20 <50 1 <0.1
0.11
0.47
1.1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1
<1 <3 <0.3 <0.3 1000
<1 <3 <0.3 <0.3 1000
<1 <3 <0.3 <0.3 1000
<1 <3 <0.3 <0.3 1000
<1 <3 <0.3 <0.3 1000
<1 <3 <0.3 <0.3 1000
<1 <3 <0.3 <0.3 1000
<1 <3 <0.3 <0.3 1000
<1 <3 <0.3 <0.3 1000
<1 <3 <0.3 <0.3 1000
<1 <3 <0.3 <0.3 1000
100
100
100
100
100
100
100
100
100
100
100
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
8-18 TBD <10
8-18 TBD <10
8-18 TBD <10
8-18 TBD <10
8-18 TBD <10
8-18 TBD <10
8-18 TBD <10
8-18 TBD <10
8-18 TBD <10
8-18 TBD <10
8-18 TBD <10
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<50
<50
<50
<50
<50
<50
<50
<50
<50
<50
<50
<20
<20
<20
<20
<20
<20
<20
<20
<20
<20
<20
<50
<50
<50
<50
<50
<50
<50
<50
<50
<50
<50
1
1
1
1
1
1
1
1
1
1
1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
0.080
0.067
0.046
0.037
0.030
0.024
0.018
0.014
0.011 0.0081 0.0062
0.34
0.29
0.20
0.16
0.13
0.10
0.078
0.059
0.046
0.035
0.027
0.81
0.68
0.47
0.38
0.31
0.24
0.18
0.14
0.11
0.08
0.06
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 9
All cleaning chemistries (aqueous and solvent): number of particles/ml >0.020um [1,calculation based on exponent of 3.0] [11]
All cleaning chemistries (aqueous and solvent): number of particles/ml >critical particle size [1] [11]
49% HF: Na, K, Fe, Ni, Cu, Cr, Co, Ca, (Ag, Au, Pd, Pt, Ru, Mo) (ppt, each) [21]
30% H2O2: Al, Na, K, Fe, Ni, Cu, Cr, Co, Ca, (Ag, Au, Ba, Cd, Mg, Mn, Mo, Pb, Pd, Pt, Ru, Sn, Ti, V, W, Zn) (ppt, each) [21]
29% NH4OH: Al, Na, K, Fe, Ni, Cu, Cr, Co, Ca, (Au, Ba, Cd, Mg, Mn, Mo, Pb, Pd, Pt, Ru, Sn, Ti, V, W, Zn) (ppt, each) [21]
100% IPA: Al, Ba, B, K, Na, K, Fe, Li, Mg, Mn, Pb, Sn, Ti, Zn, Ni, Cu, Cr, Co, Ca (ppt, each) [28]
49% HF: All other metals not listed in row above (ppt, each) [20]
30% H2O2: All other metals not listed in row above (ppt, each) [21]
29% NH4OH: all other metals not listed in row above (ppt, each) [21]
100% IPA: all other metals not listed in row above (ppt, each) [21]
IPA: High molecular weight organics (ppb)
100% IPA: Anions (ppb)
29% NH4OH: Anions (ppb)
49% HF: Anions (ppb)
49% HF: Cl (ppb)
96% H2SO4: Anions (ppb)
37% HCL: Anions (ppb)
30% H2O2: Anions (ppb)
30% H2O2: resin byproducts (ppb) e.g. total amines [41]
37% HCl: Ba, Cu, K, Pb, Li, Mn, Ni, Cu, Cr, Co, (ppt, each)
96% H2SO4: Al, Ba, B, Ca, K, Pb, Li, Mg, Mn, Na, Sn, Ti, Zn, K, Ni, Cu, Cr, Co, (ppt, each)
37% HCl: all other metals not listed in
6.5
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
5.0
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
3.8
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
2.7
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
2.3
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
1.6
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
1.3
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
1.0
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
0.81
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
0.62
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
0.47
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
0.37
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
0.28
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
0.21
30
150 150
150
150
500 500 500 500 500 10 10 500 1000 200 300 10
5 1000 1000
10000
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
10 Yield Enhancement
row above (ppt, each) [20] 96% H2SO4: all other metals not listed in row above (ppt, each) [20] BE clean solvent: Critical ions (Cu, Au, Ag, Pt, Pt, Mo, Ru) (ppt each) BE clean solvent: Other metal (ppt each) CMP slurries: scratching particles (/ml > key particle size) [9] [17] Post-CMP clean chemicals: particles >0.065 (/ml) [1] [9] [17] Post-CMP clean chemicals: elements TBD (ppt, each) [17] Plating chemicals: particles > critical size (/ml) [1] [9] [17]
Bulk Gases
(Contaminants,
ppbv) [5] N2 (O2, H2, H2O, CO, CO2, THC) [34] O2 (N2)
O2 (Ar)
O2 (H2, H2O, CO, CO2, THC) Ar (N2, O2, H2, H2O, CO, CO2, THC) [34] H2 (N2)
H2 (O2, H2O, CO, CO2, THC) He (N2, O2, H2, H2O, CO, CO2, THC) CO2 (CO, H2O, O2, THC)
Lithography and
Critical Metrology
Purge Gases (ppbv) Critical clean dry air (H2O) Critical clean dry air (H2, CO) Critical clean dry air (organics (molecular weight > benzene) normalized to hexadecane equivalent) Critical clean dry air (total base as NH3) Critical clean dry air (NH3 (as NH3)) Critical clean dry air (total acid including SO2 (as SO4)) Critical clean dry air (SO4 (as SO4)) Critical clean dry air (Each refractory compound (0rganics containing S, P, Si) Lithography nitrogen tool/maintenance purging gas supply (H2O, O2, CO2) Lithography nitrogen tool/maintenance purging gas supply
10000
500
1000 TBD
< 10
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
< 1 < 0.1 < 0.1 < 0.03 < 0.1
<500
<2000
10000
500
1000 TBD
< 10
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
< 1 < 0.1 < 0.1 < 0.03 < 0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
< 1 < 0.1 < 0.1 < 0.03 < 0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
< 1 < 0.1 < 0.1 < 0.03 < 0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
< 1 < 0.1 < 0.1 < 0.03 < 0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
< 1 < 0.1 < 0.1 < 0.03 < 0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
< 1 < 0.1 < 0.1 < 0.03 < 0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
< 1 < 0.1 < 0.1 < 0.03 < 0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
<1 <0.1 <0.1 <0.03 <0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
<1 <0.1 <0.1 <0.03 <0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
<1 <0.1 <0.1 <0.03 <0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
<1 <0.1 <0.1 <0.03 <0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
<1 <0.1 <0.1 <0.03 <0.1
<500
<2000
10000
500
1000 TBD
< 5
1000 TBD
<5 <50 <1000 <10 <5 <50 <10 <10 <1000
<1000 <2000
< 3
<1 <0.1 <0.1 <0.03 <0.1
<500
<2000
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 11
(CO)
Lithography nitrogen tool/maintenance purging gas supply (H2)
Lithography nitrogen tool/maintenance purging gas supply (organics (molecular weight > benzene) normalized to hexadecane equivalent)
Lithography nitrogen tool/maintenance purging gas supply (total base (as NH3))
Lithography nitrogen tool/maintenance purging gas supply (total acid (as SO4) including SO2)
Lithography nitrogen tool/maintenance purging gas supply (refractory compounds (organics containing S, P, Si, etc.) normalized to hexadecane equivalent)
Lithography helium tool/maintenance purging gas supply (H2O)
Lithography helium tool/maintenance purging gas supply (O2, CO2)
Lithography helium tool/maintenance purging gas supply (CO, H2)
Lithography helium tool/maintenance purging gas supply (organics(molecular weight > benzene) normalized to hexadecane equivalent)
Lithography helium tool/maintenance purging gas supply (total base (as NH3))
Lithography helium tool/maintenance purging gas supply (total acid including SO2 (as SO4))
Lithography helium tool/maintenance purging gas supply (refractory compounds (organics containing S, P, Si, etc.) normalized to hexadecane equivalent)
Number of particles > critical size (/M3) [1]
Number of particles > 0.1 m (/M3) [1]
Etchants
(Corrosive, e.g.,
BCl3, Cl2, HBr)
O2, H2O (ppbv)
Critical specified metals/total metals
<2000 < 3
< 0.15 <
0.025 <0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.40
< 500 <1/100
0
<2000 < 3
< 0.15 <
0.025 <0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.29
< 500 <1/100
0
<2000 < 3
< 0.15 <
0.025 <0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.20
< 500 <1/100
0
<2000 < 3
< 0.15 <
0.025 <0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.14
< 500 <1/100
0
<2000 < 3
< 0.15 <
0.025 <0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.10
< 500 <1/100
0
<2000 < 3
< 0.15 <
0.025 <0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.07
< 500 <1/100
0
<2000 < 3
< 0.15 <
0.025 <0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.05
< 500 <1/100
0
<2000 < 3
< 0.15 <
0.025 <0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.036
< 500 <1/100
0
<2000 < 3
<0.15 <0.025
<0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.025 < 500 <1/100
0
<2000 < 3
<0.15 <0.025
<0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.018 < 500 <1/100
0
<2000 < 3
<0.15 <0.025
<0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.013 < 500 <1/100
0
<2000 < 3
<0.15 <0.025
<0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.009 < 500 <1/100
0
<2000 < 3
<0.15 <0.025
<0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.009 < 500 <1/100
0
<2000 < 3
<0.15 <0.025
<0.1
<3500 <4000 <1000
0 < 3
< 0.15 <
0.025 <0.1
100 0.009 < 500 <1/100
0
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
12 Yield Enhancement
(ppbw) [19]
Etchants (Non-
corrosive, e.g.,
C5F8, C4F8, C4F6,
CH2F2, SF6) O2, H2O (ppbv)
Etchants (e.g. Xe)
O2, H2O (ppbv)
ALD/CVD blanket /
purge/ delivery
gases Sweep and bubbler gases for ALD/CVD volatile chemical delivery e.g., N2 (O2, H2, H2O, CO, CO2, THC) (ppb) [34]
CVD/ALD Thin Film
Process Fluids
CVD/ALD Thin Film
Process Fluids -
High k Dielectrics
High k Gate
Dielectrics e.g.,
Al2O3 and LaAlO3 High k Gate Dielectrics - TMA [75-24-1] (Assay) High k Gate Dielectrics - TMA (O2 ppm) High k Gate Dielectrics - TMA Metals each element (ppb) High k Gate Dielectrics - TMA (Silicon ppm) High k Gate Dielectrics - TMA (Hydrocarbons ppm) High k Gate Dielectrics La(FMD)3 (Lanthanum tris(N,N'isopropylformamidina te) (assay)
High k Gate
Dielectrics - Hf
oxides, silicates or
aluminates High k Gate Dielectrics - HfHTB [2172-02-3] (assay) High k Gate Dielectrics - HfHfCl4 [13499-05-3] (assay) High k Gate Dielectrics - Si source - Metal Silicates Si source - Metal Silicates - 3DMAS [15112-89-7] (assay) Si source - Metal Silicates - 4DMAS [1624-01-7] (assay) Va High k Gate Dielectrics - MgO High k Gate Dielectrics - MgOMg(EtCp)2 [114460-02-5] (assay)
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
99 99.9
99.9 99.9 98
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
99 99.9
99.9 99.9 98
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
< 1000 < 1000
tbd
99.5 <10 <150 <1 <5 tbd
tbd tbd
tbd tbd tbd
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 13
High k Capacitor
NA
NA
Dielectrics e.g.,
Al2O3 and LaAlO3
High k Capacitor
Dielectrics - TMA
[75-24-1] (see High
k Gate Dielectrics -
TMA above)
High k Capacitor
99
99
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - TDEAA
[32093-39-3 ]
(assay)
High k Capacitor
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - La(thd)3
[14319-13-2] (assay)
High k Capacitor
tbd
tbd
Dielectrics - Ta2O5
High k Capacitor
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics -
Ta(OC2H5)5
[6074-84-6] (assay)
High k Capacitor
Dielectrics - Hf
oxides
High k Capacitor
Yes
Yes
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics -HfCl4
[13499-05-3] (assay)
High k Capacitor
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - HfCl4
(Zr -ppm)
High k Capacitor
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - HfCl4
(Metals each element
-ppb)
High k Capacitor
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - HfCl4
(Hydrocarbons -
ppm)
High k Capacitor
Yes
Yes
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics HfCl4
(Hydroloysis product
Hf oxides -ppm)
High k Capacitor
99
99
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics Hf metal
organics - TDEAH
[19824-55-6 ] (assay
% by NMR)
High k Capacitor
2000
2000
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics -TDEAH
(Zr -ppm)
High k Capacitor
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics -TDEAH
(Metals each element
-ppb)
High k Capacitor
1
1
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics -TDEAH
(Hydrocarbons -%
by NMR)
High k Capacitor
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics -TDEAH
(Chloride ppm)
High k Capacitor
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics -TDEAH
(Hydroloysis product
alkylamine -ppm)
High k Capacitor
Dielectrics -Hf metal
organics , TEMAH
[352535-01-4 ]
(same as TDEAH )
High k Capacitor
99
99
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - Zr metal
organics - TEMAZ
[175923-04-3]
(assay % by NMR)
High k Capacitor
2000
2000
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - TEMAZ
- (Hf ppm)
High k Capacitor
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
14 Yield Enhancement
Dielectrics - TEMAZ
(Metals each element
ppb)
High k Capacitor
1
1
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - TEMAZ
(Hydrocarbons (%
by NMR)
High k Capacitor
5
5
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - TEMAZ
(Chloride ppm)
High k Capacitor
Yes
Yes
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - TEMAZ
(Hydroloysis product
(alkylamine) ppm )
High k Capacitor
99
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics - SrTiO3
High k Capacitor
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics -
Sr(DPM)2 (assay)
High k Capacitor
150
150
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics -
Ti(OiPA)4 [546-68-
9] (assay)
High k Capacitor
<10
<10
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
Dielectrics -
Ti(O)dpm)2
[152248-67-4]
(assay)
Spacers; misc.
<20
<20
FEOL dielectric
Films
Spacer Dielectric -
SiCN
Spacer Dielectric -
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
BTBAS [186598-40-
3] (assay)
CVD/ALD Thin Film
Process Fluids -
Low k Dielectrics
Interconnect
Dielectrics- Barrier /
Etch Stops
Barrier / Etch
Stops - SiC
Barrier / Etch Stops
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
- DMDMOS [1112-
39-6] (assay)
Barrier / Etch Stops
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
- 3MS [993-07-7]
(Assay)
Barrier / Etch Stops - tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
4MS [75-76-3]
(assay)
Barrier / Etch Stops
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
SiN / SiO2
Barrier / Etch Stops
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
SiN / SiO2 - SiH4
[7803-62-5] (assay)
Barrier / Etch Stops
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
SiN / SiO2 SiCN
Barrier / Etch Stops
>99
>99
SiN / SiO2 - 4MS
[75-76-3] (assay)
Barrier / Etch Stops
>99
>99
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
SiN / SiO2 - 3MS
[993-07-7] (assay)
Barrier / Etch Stops
- SiCO
Barrier / Etch Stops
- SiCO -
Alkylsilanes (e.g.,
Trimethylsilane
[993-07-7] ,
Tetramethylsilane
[75-76-3], DMDMOS
[1112-39-6], OMCTS
[556-67-2]) [25] - ILD
SiCO - Alkylsilanes
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
tbd
(Metals except B,
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 15
Au, Ag (ppb, each))
SiCO - Alkylsilanes (B, Au, Ag (ppb, each)) SiCO - Alkylsilanes (H2O (ppm)) SiCO - Alkylsilanes (CO, CO2 (ppm)) SiCO - Alkylsilanes (Non-methane hydrocarbons C2-C4 (ppm)) SiCO - Alkylsilanes (Nitrogen (ppm)) SiCO - Alkylsilanes (Ar+O2 (ppm)) SiCO - Alkylsilanes (Chloride (ppm)) SiCO - Alkylsilanes - 3MS [993-07-7] (assay) SiCO - Alkylsilanes - DEMS [2031-621] (assay) SiCO - Alkylsilanes -OMCTS [556-672] (assay) SiCO - Alkylsilanes - DMDMOS [111239-6] (assay)
Interconnect Bulk
Low k dielectrics Interconnect Bulk Low k dielectrics FSG / FOSG FSG / FOSG - SiF4 [7783-61-1 ] (assay) FSG / FOSG TEOS [78-10-4] (assay) FSG / FOSG SiH4 [7803-62-5] (assay) FSG / FOSG - 3MS [993-07-7] (assay)
Interconnect Bulk
Low k dielectrics -
OSG / SiCO (k = 3.0
to k = 2.7) OSG / SiCO - 3MS [993-07-7] (assay) OSG / SiCO DEMS [2031-62-1] (assay) OSG / SiCO TMCTS [2370-889] (assay) OSG / SiCO DMDMOS [111239-6] (assay) OSG / SiCO OMCTS [556-67-2] (assay)
Interconnect Ultra
low k Porous OSG /
SiCO (k < 2.7 to 2.2) Ultra low k Porous OSG / SiCO -DEMS [2031-62-1] (assay) Ultra low k Porous OSG / SiCO DEMS ( Organic Porogen (%))
CVD/ALD Thin Film
Process Fluids -
Metal Gate
Electrodes
Metal Gate
tbd tbd < 0.5 < 4
< 2 <5 < 2 >99 >99.5 >99.5 >99.5 >99.5 >99.5
99.99
>99
>99 >99.5 >99.5 >99.5 >99.5
>99.5
tbd tbd < 0.5 < 4
< 2 <5 < 2 >99 >99.5 >99.5 >99.5 >99.5 >99.5
99.99
>99
>99 >99.5 >99.5 >99.5 >99.5
>99.5
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
tbd tbd < 0.5 < 4
< 2 < 0.5 < 2 tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd
tbd tbd
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
16 Yield Enhancement
Electrodes -
Titanium
nitride/carbonitride Titanium nitride TiCl4 - Purity based upon metals ( ppbv total)
Metal Gate
Electrodes -
Ru/RuO2 Metal Gate Electrodes Ru/RuO2 - RuO4 [20427-56-9] (assay)
CVD/ALD Thin Film
Process Fluids -
MIM capacitor
Electrodes
MIM capacitor
Electrodes - Ru /
RuO2 MIM capacitor Electrodes Ru(EtCp)2 [3299296-4] (assay)
MIM capacitor
Electrodes- TiN MIM capacitor Electrodes- TiN TiCl4 [7550-45-0] (assay) MIM capacitor Electrodes - TiCl4 (Metals Purity ( ppbv total))
MIM capacitor
Electrodes - TaN MIM capacitor Electrodes - TaN PDMAT [19824-500] MIM capacitor Electrodes -TaN TAIMATA [62965453-1] (assay) MIM capacitor Electrodes - TaN TBTEMT [ 51129299-2] (assay)
MIM capacitor
Electrodes - WN MIM capacitor Electrodes - WN WF6 [7783-82-6] (assay)
CVD/ALD Thin Film
Process Fluids -
Interconnect
Conductive Films
conductive
barriers- strike
layers -Etch Stops-
Caps - etc. (cmos
and tsv's)
conductive barriers
- TaN - Tantalum
Amides (e.g.,
PDMAT [19824-50-
0], TBTDET
[169896-41-7];
TAIMATA; TBTEMT) Tantalum Amides (Critical specified metals/total metals (ppbw) ) Tantalum Amides (O2, H2O (ppbv)) Tantalum Amides
tbd tbd
tbd >99.7 tbd tbd tbd tbd <100 >99.7
tbd tbd tbd
tbd tbd
tbd >99.7
tbd tbd tbd tbd <100 >99.7
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
tbd
tbd
tbd tbd >99.7 tbd tbd <100 >99.7 tbd
tbd tbd tbd
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 17
(Hydrocarbons (ppm))
conductive barriers
- Titanium Nitride
Precursors -
halides and Amides
; TiCl4; TDMAT;
TEMAT; TDEAT;
TiCp(X)3 Titanium Nitride Precursors (Critical specified metals/total metals (ppbw) ) Titanium Nitride Precursors (O2, H2O (ppbv)) Titanium Nitride Precursors Hydrocarbons (ppm))
Titanium Nitride
Precursors TDMAT [3275-249] (assay % by NMR) TDMAT - (Purity (based on metals analyzed ( ppmv)) TDEAT [4419-47-0] ( (assay % by NMR)) TiCl4 [7550-45-0] (assay) TiCl4 Purity based upon metals ( ppbv total) TEMAT [30810354-0] (assay % by NMR)
Tantalum Nitride
Precursors -
Tantalum Amides
(e.g., PDMAT
[19824-50-0],
TBTDET [169896-
41-7]; TAIMATA;
TBTEMT) Tantalum Nitride Precursors - (Nb (ppm)) Tantalum Nitride Precursors - (Metals each element (ppb) ) Tantalum Nitride Precursors (Hydrocarbons (ppm)) Tantalum Nitride Precursors (Chloride (ppm)) Tantalum Nitride Precursors (Hydroloysis product (alkylamine)) PDMAT [19824-500] (assay % by NMR) TBTDET [16989641-7] (assay % by NMR) TAIMATA [62965453-1] (assay % by NMR) TBTEMT [ 51129299-2] (assay % by NMR)
conductive barriers
- Ruthenium metal/
RuO2 - Ru
carbonyls; Ru
amidinates e.g.,
tbd tbd <100 < 1000
< 1000 tbd Yes < 10
tbd tbd <100 >99.7 tbd tbd tbd <100 <10
tbd tbd <100 < 1000
< 1000 tbd Yes < 10
tbd tbd <100 >99.7 tbd tbd tbd <100 <10
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
tbd
tbd < 1000
tbd tbd < 1000 tbd tbd tbd
tbd tbd <100
>99.7 tbd
tbd tbd tbd tbd
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
18 Yield Enhancement
Ru(EtCp)2 [47, 48] [32992-96-4]; RuO4 [20427-56-9]
Ru(EtCp)2 [32992- NA
NA
tbd
tbd
tbd
96-4] (assay)
RuO4 [20427-56-9]
tbd
tbd
tbd
tbd
tbd
(assay)
Bulk Metal
Yes
Yes
tbd
tbd
tbd
Interconnects -
vertical - horizontal
wiring - tsv's
Tungsten metal -
99.9
99.9
99.9
99.9
tbd
Tungsten
Hexafluoride (WF6)
[7783-82-6] (assay)
Tungsten
<1/100 <1/100 <1/100 <1/100
tbd
Hexafluoride (Critical
0
0
0
0
specified metals/total
metals (ppbw)) [19]
Tungsten Hexafluoride (O2 (ppbv))
<10
<10
<10
<10
tbd
Copper metal Cu(hfac)(tmvs) [139566-53-3] ( assay)
tbd
tbd
tbd
CVD/ALD Thin Film
Process Fluids -
Semi-conducting
Thin Films
Epitaxial Si and Ge
- incuding SiGe
alloys
Epitaxial Si and Ge - 99.999 99.999 99.999 99.999
tbd
Disilane [1590-87-
0] (assay)
High Temperature Si 99.95 99.95 99.95 99.95
tbd
Epitaxy - SiHCl3 [59]
[10025-78-2] (assay)
High Temperature Si
tbd
tbd
tbd
tbd
tbd
Epitaxy - SiHCl3
(O2 (ppb))
High Temperature Si
tbd
tbd
tbd
tbd
tbd
Epitaxy - SiHCl3
(H2O (ppb))
High Temperature Si
tbd
tbd
tbd
tbd
tbd
Epitaxy - SiHCl3
(Hydrocarbons (ppb))
High Temperature Si
tbd
tbd
tbd
tbd
tbd
Epitaxy - SiHCl3
(Inboard He Leak
Rate (atm cc/sec))
High Temperature Si
<0,5
<0,5
<0,5
<0,5
tbd
Epitaxy - SiHCl3
(Dopants B, Al, P, As
(ppb))
High Temperature Si
<1
<1
<1
<1
tbd
Epitaxy - SiHCl3
(Metals like Fe (ppb))
High Temperature Si
<500
<500
<500
<500
tbd
Epitaxy - SiHCl3
(Carbon (ppb))
High Temperature Si Epitaxy - SiH4 [7803-62-5] (assay)
tbd
tbd
tbd
Epitaxial Si and Ge GeH4 [7782-65-2] (assay)
tbd
tbd
tbd
Epitaxial Si and Ge GeH4 (Carbon Dioxide ( ppmv))
Epitaxial Si and Ge GeH4 (Carbon Monoxide ( ppmv))
Epitaxial Si and Ge GeH4 (Digermane ( ppmv))
<100 <100 <100
<100 <100 <100
<100 <100 <100
<100 <100 <100
<100 <100 <100
tbd tbd tbd tbd
tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd <100 <100 <100
tbd tbd tbd tbd
tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd <100 <100 <100
tbd tbd tbd tbd
tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd <100 <100 <100
tbd tbd tbd tbd
tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd <100 <100 <100
tbd tbd tbd tbd
tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd <100 <100 <100
tbd tbd tbd tbd
tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd <100 <100 <100
tbd tbd tbd tbd
tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd <100 <100 <100
tbd tbd tbd tbd
tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd <100 <100 <100
tbd tbd tbd tbd
tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd <100 <100 <100
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 19
Epitaxial Si and Ge GeH4 (Nitrogen ( ppmv)) Epitaxial Si and Ge GeH4 (Methane(ppmv)) Epitaxial Si and Ge GeH4 (Oxygen + Argon (ppmv)) Epitaxial Si and Ge GeH4 (Trigermane( ppmv)) Epitaxial Si and Ge GeH4 (Water( ppmv)) Epitaxial Si and Ge GeH4 (Chlorogermanes( ppmv)) Epitaxial Si and Ge GeH4 (Germoxanes( ppmv)) Epitaxial Si and Ge GeH4 (Hydrogen(ppmv))
CMOS Channel
Materials Epitaxial Si Channel Replacement films Epitaxial Si Channel Replacement - GaAs / InGaAs GaAs / InGaAs Ga(CH3)3 (TMG) [1445-79-0] (assay) Ga(CH3)3 (TMG) (Metals each element( total ppb)) GaAs / InGaAs In(CH3)3 (TMI) [3385-78-2] (assay) GaAs / InGaAs arsine ( AsH3) [7784-42-1] (assay)
Epitaxial Si
Channel
Replacement - GaN
Epitaxial Si Channel Replacement - GaN - TMG [1445-790] (assay) Epitaxial Si Channel Replacement - GaN - NH3 [7664-41-7] (assay) GaN - NH3 (Iron (ppbw)) Epitaxial Si Channel Replacement - SiC Channel Replacement - SiC - SiH4 [7803-62-5] ( see above) Channel Replacement - SiC - C3H8 (propane) [74-98-6] (assay) SiC - C3H8 (propane) - (Total metals (ppbw))
Channel Stress-
Strain Management
Films
Strain Management
Films - SiGe
alloys
Low Temperature
Si/Ge Epitaxy
<10E-9
<2 <1 <20 <2 <1
<0.5 <1 <1 <5 <50
99.999 99.999
9 <100 99.999
9 99.999 <100
<10E-9
<2 <1 <20 <2 <1
<0.5 <1 <1 <5 <50
99.999 99.999
9 <100 99.999
9 99.999 <100
<10E-9 tbd tbd <2 <1 <20
<2 <1
<0.5 <1 <1 <5 <50 tbd
99.999
99.999 9
<100 tbd 99.999 9 99.999
tbd
<10E-9 tbd tbd <2 <1 <20
<2 <1
<0.5 <1 <1 <5 <50 tbd
99.999
99.999 9
<100 tbd 99.999 9 99.999
tbd
<10E-9 tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd
<10E-9 tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd
<10E-9 tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd
<10E-9 tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd
<10E-9 tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd
<10E-9 tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd
<10E-9 tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd
<10E-9 tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd
<10E-9 tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd
<10E-9 tbd tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd
tbd tbd tbd tbd tbd tbd tbd
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
20 Yield Enhancement
Low Temperature
Si/Ge Epitaxy -
Dichlorosilane
(DCS), diluteB2H6,
dilute PH3, dilute
monomethylsilane Low Temperature Si/Ge Epitaxy (O2 (ppb)) Low Temperature Si/Ge Epitaxy (H2O (ppb)) Low Temperature Si/Ge Epitaxy (Hydrocarbons (ppb)) Low Temperature Si/Ge Epitaxy Inboard He Leak Rate (atm cc/sec)
Point of Use
Purification
POUF - SiH4,
Si2H6, GeH4,
process and purge
H2, process and
purge N2 POUF - SiH4, Si2H6, GeH4 (O2 (ppb)) POUF - SiH4, Si2H6, GeH4 (H2O (ppb)) POUF - SiH4, Si2H6, GeH4 (Hydrocarbons (ppb)) POUF - SiH4, Si2H6, GeH4 (Inboard He Leak Rate (atm cc/sec))
POUF - Deposition
gases - GeH4 [7782-
65-2] POUF - GeH4 (O2, H2O (ppbv)) POUF - GeH4 (Other dopants (ppbv))
Mixing tolerance for
mixtures GeCl4 [10038-98-9]
GeH4 [7782-652] SiH2Cl2 [4109-960] Si2H6 [1590-87-0]
VIc2 Si3N4
SiH4 [7803-62-5]
Si2H6 [1590-87-0]
Other available
High purity volatile
liquid precursors
available for
Electronic Thin film
applications
(General) Deposition Gases CVD/PECVD/ ALD (General) Deposition Gases CVD/PECVD/ ALD (General) (O2, H2O (ppbv)) Deposition Gases CVD/PECVD/ ALD (General) (Critical specified metals/total metals (ppbw) )[19]
<500 <200 <1000 tbd
<10 <20 <20 <10E10
<10 <20 <20 <10E10 Yes
< 500 <1
+/-1% tbd tbd
tbd tbd
tbd
<500 <200 <1000 tbd
<10 <20 <20 <10E10
<10 <20 <20 <10E10 Yes
< 500 <1
+/-1% tbd tbd
tbd tbd
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<500 <200 <1000 tbd
<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
tbd tbd
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<500 <200 <1000 tbd
<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
tbd tbd
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<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
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<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
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<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
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<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
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<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
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<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
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<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
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<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
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<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
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<10 <20 <20 <10E10 No <10 <20 <20 <10E10 Yes tbd < 500 <1 +/-1% tbd tbd
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THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 21
Deposition Gases CVD/PECVD/ ALD (General) (Dopants (ppbv)) Metal Dopants (e.g., FeCp2, MgCp2 ) (assay) Amorphous Carbon (Double Patterning) e.g., propylene [9003-07-0] and acetylene [74-86-2] Amorphous Carbon (Double Patterning) (Other hydrocarbons (ppmv)) Amorphous Carbon (Double Patterning) (Total metals (ppbw))
Deposition gases
(e.g. NH3) Deposition gases (e.g. NH3) (O2, H2O (ppbv)) Deposition gases (e.g. NH3) (Critical specified metals/total metals (ppbw)) [19]
Deposition gases
(e.g., N2O, NO) Deposition gases (e.g. NH3) (O2, H2O (ppbv)) Deposition gases (e.g. NH3) (Critical specified metals/total metals (ppbw)) [19]
Deposition gases -
electrical dopants
(e.g. AsH3, PH3,
B2H6) electrical dopants (O2, H2 (ppb)) [36] Other dopants (ppbv) Other Dopants (Mixing tolerance for mixtures (relative variance))
Implant gases -
AsH3, PH3, BF3 Implant gases (O2, H2O (ppbv)) Implant gases (Other dopants (ppbv)) Implant gases (Mixing tolerance for F2 (relative variance)) Implant gases (Other constituents (ppbv))
Laser gases -
Litho, (e.g.
F2/Kr/Ne)
tbd
tbd tbd
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< 1000
<500 <100
tbd <100 <200
< 100 <1 +/1%
< 500 <1 +/4%
< 2500
0
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tbd tbd
tbd
< 1000
<500 <100
tbd <100
<200
< 100 <1 +/1%
< 500 <1 +/4%
< 2500
0
tbd
tbd tbd
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< 1000
<500 <100
tbd <100 <200
< 100 <1 +/1%
< 500 <1 +/4%
< 2500
0
tbd
tbd tbd
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< 1000
<500 <100
tbd <100 <200
< 100 <1 +/1%
< 500 <1 +/4%
< 2500
0
tbd
tbd tbd
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< 1000
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< 500 <1 +/4%
< 2500
0
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< 1000
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< 500 <1 +/4%
< 2500
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< 1000
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< 500 <1 +/4%
< 2500
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< 1000
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< 500 <1 +/4%
< 2500
0
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< 1000
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< 500 <1 +/4%
< 2500
0
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< 1000
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< 500 <1 +/4%
< 2500
0
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< 1000
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< 500 <1 +/4%
< 2500
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< 1000
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< 500 <1 +/4%
< 2500
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< 1000
tbd tbd
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< 500 <1 +/4%
< 2500
0
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< 1000
tbd tbd
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< 500 <1 +/4%
< 2500
0
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
22 Yield Enhancement
Laser Gases
<
<
<
<
tbd tbd tbd tbd tbd tbd tbd tbd tbd tbd
(O2, H2O (ppbv)) 500 500 500 500
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 23
Notes for Table YE3
[1] Critical particle size is based on design rule. Killer particle sizes are based on the most demanding particle level. That has been determined to be the DRAM pitch. It's typically less than Logic. Again, because it's a `roadmap' to the smallest required particle level, and not a specification, we don't include the required logic particle levels - we know they will be higher and bigger than DRAM.
[2] Airborne particle requirements are based on ISO 14644-1 at "at rest".[3]
[3] Ion/species indicated is basis for calculation. Exposure time is 60 minutes with starting surface concentration of zero. Basis for lithography projections is defined by lithography tool suppliers. Metals and organics scale as defined in the surface preparation roadmap for metallics and organics. Values listed in table are based on experience, however, all airborne molecular contaminants can be calculated as S=E*(N*V/4); where S is the arrival rate (molecules/second/cm2), E is the sticking coefficient (between 0 and 1), N is the concentration in air (molecules/cm3); and V is the average thermal velocity (cm/second). The following sticking coefficients have been proposed; SO4 = 1x10 -5, NH3 = 1x10 -6, Cu = 2x10 -5. The sticking coefficients for organics vary greatly with molecular structure and are also dependent on surface termination.
[4] Includes P, B, As, Sb
[5] Contaminant targets apply up to POE (point-of-entry). POE is defined as the entry point to the equipment or subequipment, see also the text. Benchmark data has been collected both at Point of Delivery (POD) or Point of Entry (POE), which typically show only minor differences.
[6] Critical metals and ions may include: Al, As, Ba, Ca, Co, Cu, Cr, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sn, Ti, Zn. Three different case studies were reviewed where the levels of Ca, Fe, and Ni in the UPW resulted in levels of problem densities (atoms/sq cm) on the wafer. These were reduced to acceptable levels by reducing the level of these elements in the UPW to levels well below 10 ppt. In only one case does the data exist that showed success by obtaining values below 0.5 ppt. These results drive the 1.0 ~ 0.5 ppt values.
[7] Units on all contaminants in WECC Table are often given as ppb (or ppm or ppt, we use ppb here solely for demonstration purposes). The reader should be aware that these units of parts per billion (ppb) may be ppb by mass, volume, or molar ratios. Where not designated, the following guidelines apply: Chemicals and UPW are typically ppb by mass, while gases and clean room are typically ppb by volume. In the case of the fluid acting as an ideal gas, ppb by volume is equal to ppb molar. The notable exception to the above is metals in gases that are ppb by mass. In UPW, ppb is used based on mass of water. Since 1 liter of water equals ~1 kg, 1 ppb is equal to 1 g/l.
Some parameters in the tables may be considered process variables rather than contaminants in the classical meaning. They are marked by an asterix. The limits are sometimes fluent.
[8] Detection of metals at the levels indicated will be dependent on sampling time and flow rate. Sticking Coefficients vary widely for metals. It is generally believed that Cu has a sticking coefficient 10x of other metals, and therefore the guideline for Cu could be lower.
[9] Key particle size for scratching particles depends on mean particle size of slurry. Target level will be specific to slurry and wafer geometry sensitivity.
[10] The Dissolved Nitrogen range is solely for the physical process needs of megasonics cleaning. Processes without megasonics cleaning can ignore the line item. The concentration is process specific and needs to be determined by the end user. Factors to consider include UPW temperature, partial pressure in the gas phase and megasonic energy input at the tool. Other gases, such as oxygen and hydrogen, may be used with different optimum levels. Process enhancements through chemistry associated with the other gases or other chemicals are outside of the scope of this chapter. While a relatively wide range of dissolved nitrogen values may be acceptable based on other process variables it is important to note that tight control at the desired value is warranted.
DN2 spec is considered at POE, taking into account possibility that N2 control inside the tool.
[11] As of the current year's update the finest production available sensitivity liquid particle sensor for chemicals is 0.040 m, although measurement technology is being developed at 0.020um. Values obtained by these particle counters are not directly comparable to the roadmap values and need to be normalized to critical particle size values in the roadmap using the equation and methods of Footnote A above. Interim solution to higher sensitivity particle counter is to collect data over longer time period to provide greater precision in the data near the threshold sensitivity of the counter. Most benchmark data has been collected at Point of Delivery (POD) or Point of Entry (POE) and is the basis for parameters. This particle counting efficiency is not taken into account, which may vary with particle counter model, particle materials, chemical, etc.. It is based on actual data reported.
[12] SMC Organics: Single wafer shall be oxidized to make organic-free, then wafer shall be exposed for 24 hours and top side analyzed by TD-GC-MS with 400C thermal desorption, and quantitation based on hexadecane external standard. TIC response factor per SEMI
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
24 Yield Enhancement
MF 1982-1103 (formerly ASTM 1982-99).[4] Limits determined by above method are a guideline for many organics. Note higher limits can be used for process wafers oxidized or cleaned prior to subsequent process step. Processes such as gate oxide formation, or polysilicon deposition, may be more sensitive to organics, especially high boilers such as DOP. Silicon nitride nucleation may also be more sensitive than above for some processes. Please note dopants requirement is covered in earlier section. Contamination levels are time based, and samples should be exposed for a weeks time for better sensitivity; ng/cm2/week. Total contamination level on reticles that cause problems also vary with energy exposure. These guidelines subject to change with new data currently being generated.
[13] SMC Dopants: Single wafer is first stripped with HF to yield dopant-free surface and than exposed for 24 hours. Topside of wafer is analyzed by methods known to give reliable recovery of boron. This is a guideline for dopants based on sampling in operating running fabs. Lower specifications may be required for key FEPs, especially for smaller geometries, lower thermal budgets, and for lightly-doped devices. If wafers are stripped with HF or BOE immediately prior to next thermal process, then steps may become less sensitive to surface molecular dopants, and higher limits apply. Note that BEPs tend to be orders of magnitude less sensitive to dopants than FEPs.
[14] SMC Metals: Single wafer known to meet the ITRS FEP spec of 1E10 atoms/cm2, from the Starting Materials table, is exposed to a clean environment for 24 hours. Subsequent analysis of top surface by VPD-ICP-MS or VPD-GFAA. Lower specifications may be required for key FEPs, especially for smaller geometries. If wafers are cleaned prior to the next thermal process, then air exposure during earlier steps may be less of an issue. Note that majority of environmental metallic contaminants are particles, not molecular. If total particles on wafers are kept in spec than majority of metals, most metals from the environment should be within specifications. Back-end processes (BEPs) tend to be less sensitive to metals that FEPs provided not particles. Specs of twice the incoming wafer specs are readily achievable and readily measurable in case of wafers exposed for 24 hours.
[15] SMC General: A 24-hour exposure will accentuate the contamination per wafer as wafers are often exposed too much shorter times in actual processing. The above SMC (surface molecular contamination) limits are preliminary, and no single value applies to all process steps or types of organics, dopants or metals. The SMC limits can vary substantially from process to process, and local air purification or purges may be needed to control contaminant levels.
[16] Dissolved oxygen (DO) has an effect on pre-gate oxide cleaning and the etch rate of non H-passivated SiO2 and copper structures. The level in the table is that of the most stringent. It is expected that slightly higher levels within the same order of magnitude would not have any significant effect on manufacturing processes. If the water for a specific processes need to remain at low oxygen concentrations lower levels of dissolved oxygen could provide somewhat larger process time windows before critical concentration levels are reached. It is known that some fabs consider DO a process variable and operate at DO levels 3 orders of magnitude higher than stated in the table. Corrosion rates as a function of DO are not a linear relationship for all materials, specifically copper etch rates are near a maximum at 300 ppb DO.
DO spec is considered at POE, taking into account possibility that N2 blanketing may be provided at the tool level.
[17] Uncertain at this time what target levels might be set given the variety of chemistries used in the industry and unknown sensitivity of the wafer to particles or ionic contamination in the chemical. This parameter is identified as a potentially critical one that should be considered and work is ongoing to define the correct levels.
[18] Silica may occur in UPW in a form of reactive (dissolved) or colloidal silica. Colloidal silica is considered detrimental for the semiconductor manufacturing. However, the killer particle size of currently considered generations became so small, making it impracticle to expect that the colloidal silica might be measured as delta between total and reactive silica in UPW. Hence, colloidal silica is considered to be controlled as particles down to non-detectable (as silica) level. As a result only reacive silica may occur in UPW. For practicle purposes either of the tests total or reactive silica can be used. However, measuring both total and reactive silica may be considered to confirm no presence of colloidal silica. Dissolved Silica is a potential cause for water spotting. When boron is controlled below or near limits of boron detection the level of dissolved silica is usually bellow the limits of detection as well. The silica specification is considered at POC (point of connection) based on the industry experience - no water marks were reported at the specified level. It is expected that the wafer will leach silica, adding silica level on the top of UPW level.
[19] The list of critical metals (e.g., Al, Ca, Cu, Fe, Mg, Ni, K, Si, Na) varies from process to process depending on the impact on electrical parameters such as gate oxide integrity or minority carrier lifetime as well as mobility of the metal in the substrate. The metals listed in note [G] for liquid process chemicals are of concern but the issues around metals in specialty gases are primarily around the potential for corrosion to add metal particles to the gas flow (e.g., Fe, Ni Co, P). The potential for volatile species containing metals must be considered for each specialty gas but are generally not present in the bulk gases.
[20] The following is a complete list of metal ions of concern in certain liquid chemicals: Ag, Al, As, Au, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Pd, Pt, Ru, Sb, Sn, Sr, Ti, V, W, Zn.
[21] Elements listed that are not in parentheses may cause high or some risk to device quality and may often be present in process chemicals. Elements listed that are in parentheses may cause high risk to device quality but are not typically present in process chemicals.
[22] TOC on-line measurement remains the reference detection method for the presence of total organics in UPW. Users of this roadmap are encouraged to speciate organics in their UPW. For the practical purposes, the on-line TOC measurement may be considered as critical organics, unless non-critical fraction is determined. Less than 1ppb of Total Organic Carbon was proven successful for immersion lithography operation, concerned about lens hazing.
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 25
Total Organic Carbon in UPW is defined as equivalent amount of CO2 produced from UV oxidation at 185nm wavelength inside of the UV reactor of a TOC monitoring device. Currently used online, TOC analyzers are non-specific in their measurement of organic contaminants. Some organics are expected to have higher impact to the semiconductor manufacturing than others, hence TOC specification has been replaced with critical and non-critical organics for all applications, except for immersion photolitography. Critical Organics are those with the highest boiling point. Organics with high boiling points could deposit on the wafer surface in a high temperature furnace and result in the formation of silicon carbide. This is considered a fatal defect at levels of 1.0E+12 atoms per cm2 as C. The boiling point of organic compounds is used to categorize them as a "critical". At this time, any organic compound with a boiling point higher than 200oC is considered critical. Based on past experience acceptable concentration of total critical organic compounds is <1.0ppb (as measured by on-line instrumentation). Non critical organics is proposed to be as high as 3.0 ppb. Modeling and experimental analysis are in progress to validate correlations of critical organic compounds to device defects. The end user may want to consider POU solutions for immersion litho if 1 ppb water quality is chosen to be controlled for the immersion lithography tools, independently of the type of the organics comprising TOC. The color in the ITRS table is provided to indicate the need of metrology development for online measurement of critical organics, as well additional work needed to better define the critical organics via FMEA. The organics specification is defined at the POE (Point of Entry) to the manufacturing tools, assuming that control of the organics level is provided outside of the tools, whereas the manufacturing process technology takes into account contribution by the tool materials and chemistry used.
[23] The photolithography AMC guidelines are for tools with ArF lasers only, and are based on inputs from the Litho TWG. The critical metrology guidelines are from the metrology TWG. All photolithography tools and some metrology equipments have chemical filters on the makeup air to the internals of the tools.. These filters have a finite lifetime, which is dependent on the contaminant loading. Providing a chemically cleaner environment will extend the life of these filters.
[24] Other critical ions may include inorganic ions such as Fluoride, Chloride, Nitrate, Nitrite, and Bromide, Sulfate as well as ammonium. However no reference was currently found that these ions in typical concentrations found in ultrapure water up to 50 ppt have any impact on the process. Phosphate specification level was defined at 20 ppt based on FMEA analysis. Also for organic anions such as acetate, formate, propionate, citrate, and oxalate no harmful levels have been established up to now.
The ions specification is considered at POP (point of process) due to assumption that both UPW system as well as POU filters may be used to control metals, while tool environment may contribute metal contamination. Ammonium, sulfate, and nitrite can be contributed by air.
[25] The variety of CVD and ALD precursors is continuously increasing as well as their applications. The contaminant types and levels vary widely due to the different chemical behavior. An overview about typical precursors is therefore given in attachment Precursor table.
[26.1] The maximum allowed particle concentration in UPW has been updated based on the following assumptions and considerations: A. The maximum concentration of particles in UPW is a function of the allowed defect level on the wafer as defined in the FEP Surface preparation table and particle deposition form UPW to the wafer surface. The concentration per wafer will remain constant and will only change with the wafer size (300 mm to 450 mm). The reference point will be the critical particle size. The relationship between acceptable particle concentrations on the wafer and that in UPW is based on experimental data and theoretical modeling. The user of this part of the table is encouraged to refer to the supplemental materials for specific details of the calculations. B. The definition of the "killing" particle size uses the roadmap's definition of DRAM Pitch (nm). Significant metrology issues for particles at the critical size still exist. Given the fact that the metrology gap is growing and has not been addressed for last several years, the risk management for particle control is being shifted towards the effective particle filtration and reduction of the particle challenge to the final filters. This work together with a SEMI task force produced a guide ([5] SEMI C079) for filter performance validation, as a method to control the particles on the wafer surface and mitigate the risk of particle contamination impacting yield. Similar task force has developed a test method for evaluation of the cleanliness of the virgin ion exchange resin. This document can be found in supplimental materials [6]. [26.2] Colloidal silica was previously added to emphasize higher criticality of colloidal silica particles in UPW, than the currently measured reactive and total Si in water. Existing UPW metrology is not sensitive enough to allow the detection of silica particles at the specified size as a chemical. silica particles are believed to have the ability to adsorb metals and act as a transport mechanism to potentially deposit metals on the surface of a wafer. Such metal deposition could seriously impact yield. There is no metrology that can effectively detect colloidal silica directly. And therefore, the colloidal silica specification was merged with the particles. [26.3] An additional particle requirement has been specified for EUV mask production, which requires even tighter particle control. Critical particle size remains equal to the DRAM Pitch (nm). However the allowed concentration is an order of magnitude lower than that specified for high volume manufacturing facilities (refer to supplemental information for additional details). [26.4] All particles are considered equally critical indpendently of their material of construction and their properties.
The particles specification is considered at POP (point of process) due to assumption that both UPW system as well as tool environment have to control particles, taking into account capabilities of both UPW system (including POU filters) and the tool environment contribution. However, for the practical purposes, the assumption is that most particles will be contributed by the tool, thus requiring even higher UPW quality targets at POE. Out of 12 particles per wafer (currently allowed by FEP), all 12 can be contributed by the tool (inlet valve and wafer environment). This means that UPW should contribute < 1 particle per wafer at POE.
[27] It needs to be considered that the total H2O2 anion concentration will impact the life time of the solution. Also the fluoride in the ppm range of the total chemical mixture can etch the wafer.
[28] Concentrations higher than 100 ppb could cause corrosion especially in back end of line processes.
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
26 Yield Enhancement
[29] The ultrapure water parameters provided in this table are applicable for the most critical process unless otherwise identified by additional footnotes. Further information can be found in the Supplementary tables
[30] Typical Organic Acids found in cleanroom environments that may be of concern include Acetate, Citrate, Formate, Glycolate, Lactate, Oxalate, and Proprionate. Others may also be of concern. These acids can be a significant load on acid removal filters.
[31] Ideally, continuous monitoring using online instrumentation would be preferred when practical since this can give both long term averages and catch excursions. When online monitoring is not available, an average grab sample for at least 4 hours, and not more than 24 hours is recommended, to get an average, increase sensitivity of the analysis, and avoid short term transient effects
[32] Other corrosive species include contaminants such as chlorine. Humidity is also of major concern, as it exacerbates corrosion. The humidity should be kept as low as possible in corrosive environments.
[33] Calculations for expressing ng/L into ppt are; [(ng/(L of Air) * (24.4 L of Air)/mol Air / MW(ng/nmol)) * *1000picomol/nmol ] = picomol/mol of Air = ppt molar and/or ppt volume.
[34] For certain processes such as sputtering POE purifiers may be required for N2 and Ar
[35] CO2 here is assumed to be used for wet cleaning and other equipment, not for super critical CO2 applications or dry etching.
[36] Epi - need to purify @ 45 nm; currently must add purifiers from B2H6/Germane/PH3/AsH3 - need 100 ppb
[37] The variation is defined at one location over time in at rest conditions. As reference point for the POE a location is chosen 0.3 m below the ceiling panels. Common sense requires that sensitive equipment are not installed heat sources within the cleanroom, since they may impact the temperature control between the reference point and the actual inlet to the mini-environment/tool filter.
[38] This temperature stability requirement is for immersion photolithography tools, using UPW as an immersion fluid, and based upon utility requirements projected by some tool manufacturers in 2005. It represents the maximum rate of change and stability of the temperature of the cold UPW supplied to the tool in order for the tool to maintain process required temperature stability.
[39] Values based on FMEA Risk Priority Number of 625. Users of the Table are strongly encouraged to review the FMEA and adjust as necessary for local UPW and Wafer monitoring frequency. Metals are considered to be particularly important for CMOS sensors.
The metal specification is considered at POP (point of process) due to assumption that both UPW system as well as POU filters may be used to control metals, while tool environment may contribute metal contamination.
[40] Value of 100 pptv refractory compounds is not to be seen as an absolute limit but a recommanded value derived from total dose considerations. Based on experience bottom lens deterioration from refractories is prevented for 7-10 years if an annual integral dose of 8.8E+5 ppth of refractories is not exceeded. This calculates back to an average permanent sum concentration of 100 pptv. Actual concentrations can vary in a bandwidth of factor 35 around this value.
[41] The resin by-products are only a small part of the organics in H2O2, but have shown the most serious effects on the wafer. The organics leached out from the resins are different depending on the type of resin, but have shown a much higher sticking potential than the other solvents in the H2O2. Total amines are mentioned here as an example only. Measurement of these organics is possible, e.g. by ion chromatography or liquid chromatography with mass spectrometer, but there a variety of problems, such as the sample preparation since these compounds can be very volatile/sensitive.
[42] Hydrogen peroxide (H2O2) was confirmed to be produced by UV (ultraviolet) lamps in the polish loop at the levels of up to 30 ppb, the level exceeding dissolved oxygen, which is also considered to be an oxidant. The effect of specific level of H2O2 to the wafer has not been validated yet. At this point H2O2 parameter has been added to the roadmap to indicate risks and possible need to reduce its level. Further research is needed to confirm UPW spec levels. H2O2 control is considered at POD (point of distribution) based on the assumption that no H2O2 production is expected downstream that point.
[43] More than one IDM regards the combination of 0.1 ppb limit value and the refractory compounds definition as not supported by own experience on lens integrity; General opinion is that light boiling perfluorated compounds (normally from chiller thermofluids) (e.g. Galden LT) do not have lens effects due to their lens sticking probability; A severeness rating is requested stating that Silanol and Siloxane compounds are of high importance in their contribution, S- and P- compounds following and of least importance perhalogenated compounds
[44] There is an opinion that the limit value of 0.5 ppbv total inorganic acids is too strict; Experience exists that 2 ppbv would be an acceptable limit value maintaining good yield/no or low defect conditions
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 27
[1] Cooper, D. W., "Comparing Three Environmental Particle Size Distributions," Journal of the IES, Jan/Feb 1001, 2124
[2] Pui, D. Y. H. and Liu, B.Y.H., "Advances in Instrumentation for Atmospheric Aerosol Measurement," TSI Journal of Particle Instrumentation, Vol 4. (2) Jul-Dec 1989, 32.
[3] ISO 14644-1 Cleanrooms and Associated Controlled Environments-Part 1: Classification of Air Cleanliness.
[4] SEMI MF1982-1103 (previously ASTMF 1982-99e1), Standard Test Methods for Analyzing Organic Contaminants on Silicon Wafer Surfaces by Thermal Desorption Gas Chromatography, SEMI.
[5] SEMI C79-0113 GUIDE TO EVALUATE THE EFFICACY OF SUB-15 nm FILTERS USED IN ULTRAPURE WATER (UPW) DISTRIBUTION SYSTEMS. Www.semi.org
[6] SEMI DRAFT: Document 5621A NEW STANDARD: GUIDE FOR DETERMINING THE QUALITY OF ION EXCHANGE RESIN USED IN POLISH APPLICATIONS OF ULTRAPURE WATER SYSTEM
End of Notes for Table YE3
Wafer environment control--The wafer environment control includes the ambient space around the wafer at all times, whether the wafers are open to the cleanroom air or stored in PODs/FOUPs. As the list of ambient contaminants to be controlled broadens so must measurement capabilities. Affordable, accurate, repeatable, high capture rate, real time sensors for non-particulate contamination are becoming increasingly necessary. The use of inert environments to transport and store wafers is expected to increase with process sensitivities. Pre-gate, pre-contact clean, salicidation, exposed copper, and reticle exposure are cited as processes that first require this capability. In addition, using inert environments offers the opportunity to reduce the introduction of moisture into vacuum load-lock tools, thereby decreasing contamination and load-lock pump-down times. While closed carrier purging systems exist and are evolving, tool environments that may need to become inert, such as wet sink end-stations, present a challenge. As wafer isolation technologies evolve, design and material selection of carriers and enclosures will be critical for performance in isolating the wafers from the ambient and in not contributing contaminants themselves. All carriers and enclosure materials must meet factory one specifications. In addition, the materials and designs must not promote cross-contamination between processes. Seal technology, low-outgassing, and non-absorbing materials development are key to an effective wafer and reticle isolation deployment.
Airborne molecular contamination (AMC)--Outgassing from materials of construction in the cleanroom, wafer processing equipment, post processed wafers, and wafer environmental enclosures as well as inadequate exhaust and fugitive emissions from chemicals used in wafer processing are the main sources of AMC. Only in some highly congested areas, makeup air is a significant yet temporarily important source for AMC. Oxygen and water vapor as well as low concentration atmospheric contaminants (e.g., CO, O3) can also be considered as part of the AMC burden. Acid vapors in the air have been linked to corrosion, as well as with the release of boron from HEPA filters. The impact of amines on deep ultraviolet (DUV) photoresists are well known examples of AMC affecting wafer processing. Hydrocarbon films of only a few monolayers may lead to loss of process control, especially for front-end processes. Other areas of concerns for AMC are IPA from semiconductor cleaning equipment and corrosion when Cu is exposed. The impact of AMC on wafer processing can only be expected to become more deleterious. This is not only driven by device dimensions decreasing but also by the introduction of new chemistry and recipes for future technical nodes that exhibit new defect schemes. Besides AMC creating defects to the wafer surface or bulk material Yield Enhancement group engages on defects or shortfalls in productivity that originate from the impact of AMC to production tools as reticles, metrology or exposure tools. AMC is in many cases - as for excursions - a highly dynamic phenomenon. AMC control deals mainly with prevention of AMC release for which a tight source control is mandatory. There is clearly a need for better AMC monitoring instrumentation in the clean room to measure
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
28 Yield Enhancement
AMC at the part per trillion level (by volume) in real time. Surface acoustic wave (SAW) devices and atmospheric pressure ionized mass spectroscopy (APIMS) have been used to measure low level AMC, but a larger variety of on-line methods and instrumentation is needed and expected to be available in the future, see also the link for 21AMC monitoring programs. Table YE4 and YE4a provide more detail for AMC monitoring and on-line methods.
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 29
Table YE4 AMC Monitoring Methods
Year of
Production
Flash Pitch (nm) (un-contacted Poly)(f)
DRAM Pitch (nm) (contacted)
MPU/ASIC Metal 1 (M1) Pitch (nm)
MPU Printed Gate Length (nm)
MPU Physical Gate Length (nm)
Wafer Environment Control such as Cleanroom, SMIF POD, FOUP, etc....not necessarily the cleanroom itself but wafer environment. Critical particle size (nm) [1] Number of particles (/m3) [1] [2]
2012
25 36 32 31 22
22.5 ISO CL1
Airborne Molecular Contaminants in Gas Phase (pptV, V for Volume)) [3, 7, 12,13,14,15,33].
Lithography: Point of entry ( POE) to exposure tool [23]
Limits from YE3
table
Total Inorganic Acids
5,000
Total Organic Acids [30]
Total Bases
2,000 20,000
PGMEA, Ethyl Lactate
Volatile Organics (w/ GCMS retention times benzene, calibrated to hexadecane) [31] Refractory compounds (organics containing for example S, P, Si)
5,000 26,000
100
Online Monitoring
Method
LDL
PWPD -IC [2]
*)
CRDS [3] *) UV-F [4] *)
IMS [1]
PWPD -IC [2]
*)
PTRMS [5]
*)
PWPD -IC [2]
*)
PAS [6] *)
IMS [1]
CRDS [3] *) PTRMS [5]
*)
IMS [1]
PID [8]
10 100 500 1,000 30
200
10 20 1,000 4,000 800 1,000 1,000
PID [8]
1000
PTR-
MS [5]
50
*)
Lithography: Point of entry (POE) to track & inspection tools; temporary reticle
Wet or Dry Impinger Sampling [11]
Method
LDL (pptV)
Sample volume
(L)
Samp le
flow rate (LP M)
Sample frequen
cy
IC-
Every
Ccotivnidtyu 10-100 1250000- 1-5 mo2nth
[13,14]
s
IC-
Every
Ccotivnidtyu 10-100 1250000- 1-5 mo2nth
[13,14]
s
ICCondu
1500-
Every 2
[1ct3iv,1it4y, 10-100 200
1-5
month
s
15]
Measurement methods
Passive/Diffusive Sampling (Beaker/Dry trap) [12]
TD GC-MS
Method
Samp
le
Sample
Method
LDL
LDL durati frequen challenge (pptV
on
cy
s
)
(d)
Volume (L)
Sample flow rate (mL/min)
IC-
Conducti
quarter
vity
100
7-90
ly
[13,14,1
6]
ICConducti
quarter
Use special
[13v,i1ty4,1 100 7-90 ly
GC
100
20 to 40
column
6]
For
IC- oarmgianneisc
Covnidtyucti 100 7-90 quarter only (not 100 20 to 40
[13,14,1
ly
total
bases).
5,16]
Cut at
C28.
50 to 200
50 to 200
None
100
20 to 40
50 to 200
Cut at C28
100
20 to 40
50 to 200
Breakthr
ough to
be
studied
for low
boiling
100
point S
or Si
compoun
ds. Cut
at C28.
20 to 40
50 to 200
Sample frequen
cy
Every 2
month s
t.b.d
t.b.d
t.b.d
t.b.d
Surfac e
analysi s
L Method D
L
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
30 Yield Enhancement
pod storage
Total Inorganic Acids
Total Organic Acids [30]
Total Bases
PGMEA, Ethyl Lactate
Condensable organics (definition to SEMI F21-1102, bp 150 C) Refractory compounds (organics containing for example S, P, Si)
Reticle Storage (inside stocker, inside pod, inside exposure tool library, inside inspection tool) Total Inorganic Acids
Total Organic Acids [30]
Total Bases
Condensable organics (definition to SEMI F21-1102, bp 150 C)
Refractory Compounds
Gate/Furnace area wafer environment (cleanroom FOUP ambient/tool ambient)
2,000
PWPD
-IC [2]
10
*)
CRDS [3] *)
100
ICCondu
100
UV-F
ctivity
500
[13,14]
[4] *)
IMS [1]
1,000
2,000
PWPD
-IC [2]
30
IC-
*)
PTR-
Ccotivnidtyu 100
MS [5]
200
[13,14]
*)
PWPD
-IC [2]
10
IC-
*)
Condu
2,000
PAS [6] *)
20 [1ct3iv,1it4y, 100
15]
IMS [1]
1,000
PTR-
MS [5]
800
*)
5,000
IMS [1]
1,000
PID [8]
1,000
PTR-
1,000
MS [5]
50
*)
PTR-
MS [5]
50
*)
tbd
L-[I9M] S 800
PID [8]
1,000
PWPD
-IC [2]
10
*)
IC-
<200
SRIMS [7]
50
Condu ctivity
10
*)
[13,14]
C[R3]D*)S 100
PWPD
-IC [2]
30
IC-
<200
*)
PTR-
Ccotivnidtyu 10
MS [5]
200
[13,14]
*)
PWPD
IC-
-IC [2] *)
30
Condu
<200
ctivity
10
PAS [6] *)
[13,14,
20
15]
PTR-
< 100
MS [5]
50
*)
PTR-
MS [5]
50
*)
tbd
L-[I9M] S 800
Every
IC-
250000- 1-5 mo6nth Covnidtyucti 100 7-90 qualyrter
s
[13,14]
Every
IC-
Use
250000- 1-5 mo6nth Covnidtyucti 100 7-90 qualyrter spGeCcial 100 20 to 40
s
[13,14]
column
Every
ICConducti
quarter
250000- 1-5 mo6nth vity 100 7-90 ly
s [131,51]4,
None
100
20 to 40
CCu2t 8at 100
Breakthr
ough to
be
studied
for low
boiling
100
point S
or Si
compoun
ds. Cut
at C28.
20 to 40 20 to 40
Every
IC-
1250000- 1-5 mo6nth Covnidtyucti 100 7-90 qualyrter
s
[13,14]
Every
IC-
Use
1250000- 1-5 mo6nth Covnidtyucti 100 7-90 qualyrter spGeCcial 100 20 to 40
s
[13,14]
column
Every
ICConducti
quarter
1250000- 1-5 mo6nth vity 100 7-90 ly
s [131,51]4,
Cut at
C28.
Does not
apply to
100
inside
POD
sampling
20 to 40
Breakthr
ough to
be
studied
for low
boiling
100
point S
or Si
compoun
ds. Cut
at C28.
20 to 40
50 to 200
50 to 200 50 to 200
50 to 200
50 to 200
50 to 200
50 to 200
2x annual
t.b.d t.b.d t.b.d
2x annual
t.b.d t.b.d
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Total metals [8] (E+10 atoms/cm2/week)
10
Dopants [4] (E+10 atoms/cm2/week; front end of line only)
PTR-
10
MS [5]
50
*)
Volatile Organics (w/ GCMS retention times benzene, calibrated to hexadecane) [31]
Gate/Furnace
area wafer
environment
(FOUP inside) Total metals [8] (E+10 atoms/cm2/day)
20000
PID [8]
1000
0.5
Dopants [4] (E+10 front end of line only)
PTR-
0.5
MS [5]
50
*)
Volatile Organics (w/ GCMS retention times benzene, calibrated to hexadecane) [31]
tbd
Yield Enhancement 31
Cut at C28
100
20 to 40
50 to 200
Witnes
s wafer
+ VPD
1
ICP-
.
MS
0
[17] or
E
TXRF
+
[18]
0
(nbouttfor 9
light
a
the
t
eleme
o
nts Li,
m
Na, Al
s
& Mg)
/
or
c
equival m
eSnEtM. I 2
E45-
1101.
1
Witnes .
s wafer 0
+ DSE
E
ICP-
+
MS
0
[19]
9
(TOF-
SIMS
a
[20]
t
also or o
equival m
ent).
s
SEMI
/
E45-
c
1101.
m
2
t.b.d
Cut at
C28. Be
aware
that the
FOUP is
not tight
and will be
10 to 20 but
replenish ed with
always identical
gases from
100
volumes,
50 to
t.b.d
temperat
200
outside the
ure and backgrou
FMOakUeP. nd
sure the
surround
ing
environm
ent is
clean
Witnes
s wafer
+ VPD
1
ICP-
.
MS
0
[17] or
E
TXRF
+
[18]
0
(nbouttfor 9
light
a
the
t
eleme
o
nts Li,
m
Na, Al
s
& Mg)
/
or
c
equival m
eSnEtM. I 2
E45-
1101.
1
Witnes .
s wafer 0
+ DSE
E
ICP-
+
MS
0
[19]
9
(TOF-
SIMS
a
[20]
t
also or o
equival m
ent).
s
SEMI
/
E45-
c
1101.
m
2
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
32 Yield Enhancement
enough.
SMC (surface molecular condensable) organics on wafers, ng/cm2/day [12]
Salicidation Wafer Environment (Cleanroom FOUP ambient) Total Inorganic Acids
Total Organic Acids [30]
Salicidation Wafer Environment (FOUP inside; wafer environment) Total Inorganic Acids
Total Organic Acids [30]
Exposed Copper Wafer Process Environment (Cleanroom ambient, Tool inside) Total Inorganic Acids
Total Bases
Total Organic Acids [30]
Total other corrosive species [32]
H2S
tbd
500 5000
500 5000
500 2000 500 1000 1000
PWPD
-IC [2]
10
*)
IC-
CRDS *)
100
Condu ctivity
100
[3]
[3, 4]
U[4V]-*F) 500
PWPD
-IC [2]
30
IC-
*)
PTR-
Ccotivnidtyu 100
MS [5]
200
[3, 4]
*)
200500
200500
PWPD
-IC [2]
10
IC/
*)
Condu
C[R3]D*)S 100 c[t1iv3it,y 100
U[4V]-*F) 500 14]
PWPD
-IC [2]
30
*)
IC/
Condu
ctivity
100
PTR-
[13,
MS [5]
200
*)
14]
200500
200500
PWPD -IC [2]
*)
CRDS [3] *) UV-F [4] *) gg PAS [6] *)
IMS [1]
PWPD -IC [2]
*)
PTRMS [5]
*)
IMS [1]
UV-F [4] *)
10 100 500 10 20 1,000 30 200
1,000
500
IC/
Condu
ctivity
100
[13,
14]
IC/
Condu
ctivity
100
[13,
14, 15]
IC/ Condu ctivity
[13, 14]
IC/ Condu ctivity
[13, 14]
100
100/10 00
200500
200500
200500
200500
Witnes 0. sTDw-afer 1
GC/M
n
S
g
SEMI
/
MF
c
1982-
m
1103
2
IC1-5 qualyrter Covnidtyucti 100 7-90 qualyrter
[3, 4]
IC-
Use
1-5 qualyrter Covnidtyucti 100 7-90 qualyrter spGeCcial
100
20 to 40
[3, 4]
column
50 to 200
quarter ly
IC/ 1-5 qualyrter Cvoitynd[1u3c,ti 100 7-90 qualyrter
14]
10 to 20
but
IC/
Use
always
1-5
quarter Conducti
100
7-90 quarter
special
identical
100
volumes,
50 to
t.b.d
ly
vity [13,
14]
ly
GC
column
temperat
200
ure and
backgrou
nd
Every
IC/
1-5 mo6nth Cvoitynd[1u3c,ti 100 7-90 qualyrter
s
14]
For
organic
Every
IC/
amines
1-5 mo6nth Cviotynd[u1c3t,i 100 7-90 qualyrter ontloyta(nl ot 100 20 to 40
s
14, 15]
bases).
Cut at
C28.
Every
IC/
Use
1-5 mo6nth Cvoitynd[1u3c,ti 100 7-90 qualyrter spGeCcial 100 20 to 40
s
14]
column
Every
IC/
1-5 mo6nth Cvoitynd[1u3c,ti 100/- 7-90 qualyrter
s
14]
50 to 200
50 to 200
t.b.d
2x annual
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 33
Total sulphur compounds
Exposed Aluminum Wafer Process Environment (Cleanroom ambient, Tool inside) Total Inorganic Acids
Total Bases
Total Organic Acids [30]
Total other corrosive species [32]
H2S
Total sulphur compounds
Exposed Copper Wafer Environment (FOUP inside) Total Inorganic Acids
HCl
HF
HBr
HNOx
Total Organic Acids [30]
2500
IMS [1]
UV-F [4] *)
IMS [1] PTRMS [5]
*)
1,000 500 1,000 1000
500
tbd tbd 1000 tbd tbd
PWPD -IC [2]
*)
CRDS [3] *) UV-F [4] *)
PWPD -IC [2]
*)
PAS [6] *)
IMS [1]
CRDS [3] *) PWPD -IC [2]
*)
PTRMS [5]
*)
IMS [1]
UV-F [4] *) IMS [1] UV-F [4] *) IMS [1] PTRMS [5]
*)
10 100 500 10 20 1,000 4,000 30 200
1,000
500 1,000 500 1,000 1000
IC-
Condu
ctivity
100
[13,
14]
IC/
Condu
ctivity
100
[13,
14, 15]
ICCondu ctivity
[13, 14]
ICCondu ctivity
[13, 14]
100
100/10 00
200500
200500
200500
200500
Every
IC/
1-5 mo6nth Cvoitynd[1u3c,ti 100 7-90 qualyrter
s
14]
For
organic
Every
IC/
amines
1-5 mo6nth Cviotynd[u1c3t,i 100 7-90 qualyrter ontloyta(nl ot 100 20 to 40
s
14, 15]
bases).
Cut at
C28.
Every
IC/
Use
1-5 mo6nth Cvoitynd[1u3c,ti 100 7-90 qualyrter spGeCcial 100 20 to 40
s
14]
column
Every
IC-
1-5 mo6nth vCitoynd[u1c3t,i 100/- 7-90 qualyrter
s
14]
50 to 200
50 to 200
t.b.d
2x annual
500 200 5000 tbd tbd
100
PWPD
-IC [2]
200 **)
IC-
*)
Condu
C[R3]D*)S 100 c[t1iv3it,y 100
U[4V]-*F) 500 14]
IC-
PWPD
Condu
-IC [2]
200 **)
ctivity
100
*)
[13,
14]
PWPD
-IC [2]
200 **)
IC-
*)
Condu
C[R3]D*)S 100 c[t1iv3it,y 100
14]
IMS [1]
1,000
IC-
Condu
IMS [1]
1,000
ctivity
100
[13,
14]
PWPD -IC [2]
*)
200 **)
ICCondu
ctivity
100
CLD [10]
200
[13, 14]
IC-
PWPD
Condu
-IC [2]
400 **)
ctivity
100
*)
[13,
14]
as
IC-
as
200-
1-5
neede
Conducti
100
7-90
neede
500 d vity14[]13, d
as
IC-
as
200-
1-5
neede
Conducti
100
7-90
neede
500 d vity14[]13, d
as
IC-
as
200-
1-5
neede
Conducti
100
7-90
neede
500 d vity14[]13, d
as
IC-
as
200-
1-5
neede
Conducti
100
7-90
neede
500 d vity14[]13, d
as
IC-
as
200-
1-5
neede
Conducti
100
7-90
neede
500 d vity14[]13, d
10 to 20
but
as ConICd-ucti
as spUesceial
always
identical
50 to
as
250000- 1-5 neede vity [13, 100 7-90 neede GC 100 volumes, 200 neede
d
14]
d column teumrepaenrdat d
backgrou
nd
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
34 Yield Enhancement
Total bases
Total other corrosive species [32] H2S Total sulphur compounds
Exposed Aluminum Wafer Environment (FOUP inside) Total Inorganic Acids
HCl
HF
HBr
HNOx
Total Organic Acids [30]
Total other corrosive species [32]
Cut at
PWPD -IC [2]
*)
200 **)
C28. Be aware that the
FOUP is
not tight
and will
[P6A] *S) 20
be replenish
10 to 20 but
IC-
IC-
ed with
always
tbd
Ccotivnidtyu 100 200- 1-5 neaesde Conducti 100 7-90 neaesde gfarosmes 100 vidoelunmticeasl, 50 to t.b.d
[13, 500 d v1it4y, [1153],
d
outside
temperat
200
IMS [1]
1,000
14, 15]
the
ure and
FOUP.
backgrou
Make
nd
sure the
surround
CRDS [3] *)
4,000
ing environm
ent is
clean
enough.
IC-
IC-
tbd IMS [1] 1,000 Cc[ot1ivn3idt,yu 10000/10 250000- 1-5 neaedsde Cviotynd[u1c3t,i 100 7-90 neaedsde
14]
14]
UV-F *)
500
tbd
[4]
IMS [1]
1,000
U[4V]-*F) 500
5000
IMS [1]
PTRMS [5]
*)
1,000 1000
tbd 100 200 tbd tbd tbd 1000
PWPD -IC [2]
*)
CRDS [3] *) UV-F [4] *)
IMS [1]
PWPD -IC [2]
*)
PWPD -IC [2]
*)
CRDS [3] *)
IMS [1]
PWPD -IC [2]
*)
CLD [10]
PWPD -IC [2]
*)
PTRMS [5]
*)
IMS [1]
200 **) 100 500 1,000 200 **)
200 **) 100
1,000 200 **) 200 400 **)
200
1,000
IC-
Condu
ctivity
100
[13,
14]
IC-
Condu
ctivity
100
[13,
14]
IC-
Condu
ctivity
100
[13,
14]
IC-
Condu
ctivity
100
[13,
14]
IC-
Condu
ctivity
100
[13,
14]
IC-
Condu
ctivity
100
[13,
14]
ICCondu ctivity
[13, 14]
100/10 00
200500
200500
200500
200500
200500
200500
200500
as
IC-
as
Conducti
100
7-90
neede
1-5 needde vity d
[13,14]
as
IC-
as
Conducti
100
7-90
neede
1-5 needde vity [13, d
14]
as
IC-
as
Conducti
100
7-90
neede
1-5 needde vity [13, d
14]
as
IC-
as
Conducti
100
7-90
neede
1-5 needde vity [13, d
14]
as
IC-
as
Conducti
100
7-90
neede
1-5 needde vity [13, d
14]
as
IC-
as
Use
Conducti
100
7-90
neede
special
1-5 needde vity [13,
d
GC
14]
column
as
IC-
as
Conducti
100
7-90
neede
1-5 needde vity [13, d
14]
10 to 20
but
always
identical
100
volumes,
temperat
ure and
backgrou
nd
50 to 200
as neede
d
Methods and instruments are known and are being optimized Methods and instruments are known and in preparation for production
Methods and instruments are in beta tool status under qualification
Footnotes from first row : Please refer to YE3 table footnotes.
[23] note amendment: entry to scanner has two applications: supply gas with 10 ppt LDL and filtered ambient air with 100 ppt LDL.
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 35
Footnotes [1] IMS Ion Mobility Spectrometry; for method key features and capabilities please refer to the methods overview table (YE 4a) [2] PWPD-IC Parallel Wet Plate Denuder Ion Chromatography; for method key features and capabilities please refer to the methods overview table (YE 4a) [3] CRDS Cavity Ring Down Spectroscopy; for method key features and capabilities please refer to the methods overview table (YE 4a) [4] UV-F UV Fluorescence; for method key features and capabilities please refer to the methods overview table (YE 4a [5] PTR-MS Proton Transfer Mass Spectrometry; for method key features and capabilities please refer to the methods overview table (YE 4a) [6] PAS Photoaccoustic Spectrometry; for method key features and capabilities please refer to the methods overview table (YE 4a) [7] SRI-MS Switchable Reactive Ion MS (matrix nitrogen or inerts); for method key features and capabilities please refer to the methods overview table (YE 4a) [8] PID Photoionization Detektor; for method key features and capabilities please refer to the methods overview table (YE 4a) [9] L-IMS Laser Induced Ion Mobility Spectrometry; for method key features and capabilities please refer to the methods overview table (YE 4a) [10] CLD Chemiluminescence Detection of NO y compounds, for method key features and capabilities please refer to the methods overview table (YE 4a) *) Method is capable to detect and quantity individual compounds. Sum values are therefore the results of summing up individual concentrations **) LDL calculated from LDL of unrestricted volume & sampling time (clean room) to restricted volume & sampling time (FOUP) [11] Impinger sampling for FOUP and other micro-environments is only applicable for continuous purge outgas testing, not for static volume testing, due to the limited volume of the device. [12] Due to its long sampling time, passive sampling (formerly beaker sampling) is recommended only for long-term averaging of AMC concentrations. [13] Ion Chromatography Mass Spectrometry (IC/MS) may be used to identify unknown species [14] Capillary electrophoresis mass spectrometry (CE/MS) may be used with probable higher detection limits [15] Liquid chromatography mass spectrometry (LC/MS) may be used for organic bases [16] Open beakers are not suitable for compressed gas analysis. Dry passive samplers would work. [17] VPD ICP-MS: Vapor phase deposition inductively coupled plasma mass spectrometry [18] TXRF: Total reflectance X ray spectroscopy [19] DSE ICP-MS: Drop scan extraction inductively coupled plasma mass spectrometry [20] TOF-SIMS: Time of flight secondary ion mass spectrometry
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
36 Yield Enhancement
Class and type of Molecular Contamination (to SEMI F 21-1102, ITRS Definitions of AMC and CAS-N)
CAS-N
Limit of quantification classified Class 1 (10 pptv) to Class 5 (100'000 pptv)
Measurement Range (pptv)*
MA (Molecular Contamination of Acid or acid precursor type) Total Inorganic Acids as sum value****** HF (Hydrogen Fluoride) as individual compound
HCl (Hydrogen Chloride) as individual compound
HBr (Hydrogen Bromide) as individual compound HNO2 (nitrous acid) as individual compound HNO3 (nitric acid) as individual compound NO y (representing HNO3 + HNO2) NOx (representing NO+NO2) SO2 (Sulfur Dioxide) as individual compound
Others (as individual compounds) Total Organic Acids as sum value****** HFc (Formic Acid) as individual compound
HAc (Acetic Acid) as individual compound
HPr (Propionic Acid) as individual compound HLac (Lactic Acid) as individual compound Hox (Oxalic Acid) as individual compound Others (as individual compounds)
7664-39-3 7664-39-3 7664-39-3 7664-39-3 7664-39-3 7647-01-0 7647-01-0 7647-01-0 7647-01-0 10035-10-6 10035-10-6 7782-77-6 7697-37-2
7446-09-5 7446-09-5 7446-09-5 7446-09-5 7446-09-5
64-18-6 64-18-6 64-18-6 64-19-7 64-19-7 64-19-7 79-09-4 79-09-4 50-21-5 144-62-7
Class 3 (1000 pptv) Class 1 (10 pptv) Class 2 (30 pptv) Class 2 (100 pptv)
Class 3 (1000 pptv) Class 6 (200 000 pptv)
Class 1 (10 pptv) Class 3 (500pptv) Class 3 (1000 pptv) Class 6 (200 000 pptv) Class 3 (1000 pptv) Class 6 (200 000 pptv) Class 1 (10 pptv) Class 1 (10 pptv) Class 2 (100 pptv) Class 3 (1000 pptv) Class 1 (10 pptv) Class 2 (20 pptv) Class 2 (100 pptv) Class 3 (500 pptv) Class 6 (200 000 pptv)
Class 2 (30 pptv) Class 3 (500 pptv) Class 6 (200 000 pptv) Class 2 (30 pptv) Class 3 (500 pptv) Class 6 (200 000 pptv) Class 6 (200 000 pptv) Class 3 (500 pptv) Class 3 (500 pptv) Class 3 (500 pptv)
0-5E+5 pptv
0 - 10E+6 pptv 0-10E+8 pptv 0-5E+5 pptv 0-5E+7 pptv
0-2.5E+9 pptv 0-5E+5 pptv 0-5E+7 pptv 0-5E+5 pptv 0-5E+7 pptv
0-1E+6 pptv 0-4E+5 pptv
0-1E+5 pptv 0-5E+5 pptv 0-5E+7 pptv
0-10E+7 pptv 0-5E+7 pptv
0-10E+7 pptv 0-5E+7 pptv 0-5E+7 pptv 0-10E+7 pptv 0-10E+7 pptv 0-10E+7 pptv
MB (Molecular Contamination of alkaline nature, bases) Total Base as sum value****** NH3 (Ammonia) as individual compound
TMAH (Trimethylammoniumhydroxide) as individual compound Me3N (Trimethylamine) as individual compound Other amines as individual compounds, MEA, N-MEA
NMP (N-Methylpyrolidone) as individual compound
Total reduced Nitrogen, total amine****** Other airborne compounds or alkaline nature
7664-41-7 7664-41-7 7664-41-7 7664-41-7
75-59-2 75-59-2 75-50-3
872-50-4 872-50-4 872-50-4
Class 3 (1000 pptv) Class 2 (20 pptv) Class 1 (10 pptv)
Class 3 (1000 pptv) Class 4 (4000 pptv) Class 2 (100 pptv) Class 3(700 pptv)
Class 1 (10 pptv) Class 3 (1000 pptv) Class 3 (1000 pptv)
Class 1 (10 pptv) Class 3 (1000 pptv) Class 3 (1000 pptv) Class 3 (500 pptv)
0-5E+5 pptv 0-1E+6 pptv
0-5E+5 pptv 0-400E+6 pptv 0-10E+7 pptv 0-10E+7 pptv
0-1E+6 pptv 0-5E+5 pptv 0-1E+6 pptv 0-5E+5 pptv 0-1E+6 pptv 0-1E+6 pptv
Molecular Contamination with Corrosive effects Total Corrosive Species as sum value****** F2 (Fluorine) as individual value Cl2 (Chlorine) as individual value I2 (Iodine) as individual value
Ozone
other corrosive species as individual value
7782-41-4 7782-50-5 7553-56-2
Class 3 (1000 pptv) Class 3 (500 pptv)
0-4E+5 pptv 0-1E+6 pptv
MC (Molecular Contamination of Condensable Nature, Organics) Condensable Organics to SEMI F-21-95 (bp > 150 C), sum value****** Volatile Organic Compounds (VOC) retention time > benzene PGMEA (Methoxy-propyl-acetate) as individual compound
EL (Ethyl lactate) as individual compound
Other organic compounds (as individual compounds)
108-65-6 108-65-6 108-65-6 97-64-3 97-64-3 97-64-3
Class 3 (1000 pptv)
Class 2 (100 pptv) Class 3(700 pptv) Class 3 (1000 pptv) Class 2 (100 pptv) Class 3(600 pptv) Class 3 (1000 pptv)
0-5E+5 pptv
0-10E+7 pptv 0-10E+7 pptv 0-5E+5 pptv 0-10E+7 pptv 0-10E+7 pptv 0-5E+5 pptv
Molecular Contamination of refractive type Total Refractory compounds (containing Si, P, S) as sum value****** HMDS (Hexamethyl-di-silazane) as individual compound
TMS (Trimethyl-silanol) as individual compound HMDSO (Hexa-methyl-di-siloxane) as individual compound
other linear siloxane compounds (as individual compounds) other cyclic siloxane compounds (as individual compounds) organo-phosphorous compounds (as individual compounds) organo-sulfur compounds (as individual compounds)
999-97-4 999-97-4 999-97-3 999-97-4 1066-40-6 1066-40-6 107-46-0 107-46-0 107-46-0
Class 2(50 pptv) Class 3(800 pptv) Class 3(1000 pptv) Class 3 (1000 pptv) Class 2(50 pptv) Class 3(1000 pptv) Class 2(50 pptv) Class 3(1000 pptv) Class 3 (1100 pptv) Class 2(50 pptv) Class 3(1000 pptv) Class 2(50 pptv) Class 3(1000 pptv) Class 2(50 pptv) Class 3(1000 pptv)
0-10E+8 pptv 0-1E+5 pptv 0-10E+7 pptv 0-5E+5 pptv 0-10E+8 pptv 0-10E+7 pptv 0-10E+8 pptv 0-10E+7 pptv 0-10E+5 pptv 0-10E+8 pptv 0-10E+7 pptv 0-10E+8 pptv 0-10E+7 pptv 0-10E+8 pptv 0-10E+7 pptv
MD (Molecular Contamination of Dopant type) Total Dopant compounds (n-dopants or p-dopants)****** Boron compounds (airborne, of inorganic nature) Boron compounds (airborne, of organic nature) Phosphorous compounds (airborne, of inorganic nature), PH3 Phosphorous compounds (airborne, of organic nature) Arsenic compounds (airborne, or inorganic nature), AsH3 Arsenic compounds (airborne, or organic nature) Other dopant compounds (as individual compound)
7802-51-2 7784-42-1
Class 5 (100'000 pptv) Class 5 (100'000 pptv)
0-5E+6 pptv 0-5E+6 pptv
Molecular Contamination of Sulfurous Nature Total Sulfurous Compounds as sum value****** H2S (hydrogen sulfide) as individual compound
SO2 (Sulfur Dioxide) as individual compound
7783-06-4 7783-06-4 7783-06-4 7783-06-4 7446-09-5 7446-09-5 7446-09-5 7446-09-5
Class 3 (500 pptv) Class 3 (1000 pptv) Class 4 (10 000 pptv) Class 5 (100 000 pptv)
Class 1 (10 pptv) Class 2 (100 pptv) Class 2 (20 pptv) Class 3 (500 pptv)
0-5E+5 pptv 0-5E+5 pptv 0-5E+5 pptv 0-5E+8 pptv
0-1E+5 pptv
0-5E+5 pptv
Mercaptanes as individual compounds DMS (Dimethyl-sulfide) as individual compound
DMSO (Dimethly-sulfoxide) as individual compound
75-18-3 75-18-3 67-68-5
Class 3(1000 pptv) Class 3(1000 pptv) Class 3 (1000 pptv) Class 3(1000 pptv)
0-10E+7 pptv 0-10E+7 pptv 0-5E+5 pptv 0-10E+7 pptv
* Range that can be calibrated and renders reliable results ** Indicate also typical sampled volume to render a datapoint/reading *** Indicate typical time period for drift consideration and zero point re-calibration **** Indicate typical time period for span drift consideration and re-calibration ***** Monitor can be used in an automated multi-sampling point environment; how many ports/time resolution? ****** "Total" analyzers may have different response factors to individual contaminants, and therefore may over or under report actual gas-phase concentrations.
Besson et. al. (2006), Ammonia trace measurments at ppbv level based on near-IR photoaccoustic spectroscopy, Appl. Phys. B (2006) Feilberg et. Al (2010), Odorant Emissions from intensive pig production measured by on-line PTR-Mass Spectrometry, Environ. Sci. Technol. (2010), 44, 5894-5900 Jaksch et. Al. (2004), The effect of ozone treatment [ ] using PTR-MS, Int. Journal of Mass Spectrometry 239 (2004) 209-214 Takeuchi et.Al. (2011), Parallel-Plate Wet Denuder Coupled Ion Chromatograph for Near-Real-Time Detection of Trace Acid Gases in Clean Room Air, Proceedings on ISSM (2010), IUC-P-058I Warnecke et. Al (2003), Validation of atmospheric VOC measurments by PTR-MS using a ga-chromatographic pre-separation method, Environ. Sci. Technol. (2003), 37, 2494-2501
Matrix (air, others)
air air & inerts
air air & inerts
air air air & inerts air & inerts air air air air air & inerts air & inerts air air air & inerts nitrogen Air air air
air & inerts air air
air & inerts air air air air air air
air air air & inerts air air & inerts air air
air & inerts air air air air air air
air
air
air
air air air air air air
air air air air air air air air air air air air air air air
air
air
air air air air & inerts air & inerts air nitrogen air
air air air air
Data interval (sec)
30 900
5 1 30
900 1 30
30
900 900 10 30 900 var. 30
5
Sample flow** (ml/min)
response time t95 rise (sec)
recovery time t05 decline (sec)
zero point*** drift (%/month)
span drift**** (%/month)
interference to (% of signal)
service interval (months)
multipoint sampling capability*****
measurement principle
literature reference ( publication with IDM/academia)
250 5000 < 600 1000 250
5000 1000 250
250
5000 5000 300 250 5000 501000 250 700
< 1 900 < 600
< 1
900
< 1
< 1
900 900
3 < 1 900 1 < 1 120
< 180 900 < 600
< 180
900
< 180
< 180
900 900 10 < 20 900 0.2 < 20 80
0% (autozero)
12 months 0
0% (autozero)
0 0% (autozero)
0% (autozero)
5% 0.5 ppb/month
5%
5% 5%
<1% 0% (autozero)
none 0% (autozero)
<0,1%
<1% 5%
5% <0,1%
5% of NOx 5% of HCl 5% of NOx
5% of NOx 5% of NOx
CO2
5% of NOx 2% of NOx
36 months 1 month
12 months no service required
36 months
1 month no service required
36 months
3-6 months
1 month 1 month 12 months 36 months 1 month 6 months 36 months 3 months
up to 64 ports yes
up to 16 ports yes
up to 64 ports
yes Yes up to 64 ports
up to 64 ports
yes yes yes up to 64 ports yes yes up to 64 ports
Ion Mobility Spectrometry (IMS) Parallel-Wet-Plate Denuder/IC (PWPD-IC) Cavity Ring-Down Spectroscopy (CRDS)
Continuous Wave - CRDS Ion Mobility Spectrometry (IMS)
Fourier-Transform IR (FT-IR) Parallel-Wet-Plate Denuder/IC (PWPD-IC)
Continuous Wave - CRDS Ion Mobility Spectrometry (IMS)
Fourier-Transform IR (FT-IR) Ion Mobility Spectrometry (IMS)
Fourier-Transform IR (FT-IR) Parallel-Wet-Plate Denuder/IC (PWPD-IC) Parallel-Wet-Plate Denuder/IC (PWPD-IC)
Chemiluminescence CLD Ion Mobility Spectrometry (IMS) Parallel-Wet-Plate Denuder/IC (PWPD-IC) Switchable Reactive Ion MS (SRI-MS) Ion Mobility Spectrometry (IMS)
UV Fluorescence (UVF) Fourier-Transform IR (FT-IR)
M. Takeuchi et. Al. (2011) John C. Bosch Jr, dec 2010 - US EPA
M. Takeuchi et. Al. (2011)
M. Takeuchi et. Al. (2011) M. Takeuchi et. Al. (2011) M. Takeuchi et. Al. (2011)
900
5000
900
900
5
50
5
10
900
5000
900
900
5
50
5
10
5
50
5
10
5
50
5
10
5
50
5
10
1 month 3 months
1 month 3 months
3 months 3 months 3 months
yes
Parallel-Wet-Plate Denuder/IC (PWPD-IC) M. Takeuchi et. Al. (2011)
yes
Proton Transfer MS (PTR-MS)
Fourier-Transform IR (FT-IR)
yes
Parallel-Wet-Plate Denuder/IC (PWPD-IC) M. Takeuchi et. Al. (2011)
yes
Proton Transfer MS (PTR-MS)
Fourier-Transform IR (FT-IR)
Fourier-Transform IR (FT-IR)
yes
Proton Transfer MS (PTR-MS)
yes
Proton Transfer MS (PTR-MS)
yes
Proton Transfer MS (PTR-MS)
30
250
< 1
< 60
0% (autozero)
5%
36 months
up to 64 ports
Ion Mobility Spectrometry (IMS)
15
1000
60
60
< 2%
< 2%
water vapour
12 months
yes
Photoaccoustic Spectrometry (PAS)
Besson et al. (2006)
900
5000
900
900
1 month
yes
Parallel-Wet-Plate Denuder/IC (PWPD-IC) M. Takeuchi et. Al. (2011)
30
250
< 1
< 60
0% (autozero)
5%
36 months
up to 64 ports
Ion Mobility Spectrometry (IMS)
1
1000
no service
yes
Continuous Wave - CRDS
5
50
5
10
3 months
yes
Proton Transfer MS (PTR-MS)
5
50
5
10
3 months
yes
Proton Transfer MS (PTR-MS)
900
5000
900
900
1 month
yes
Parallel-Wet-Plate Denuder/IC (PWPD-IC) M. Takeuchi et. Al. (2011)
5
50
1
2
3 months
yes
Proton Transfer MS (PTR-MS)
30
250
< 1
< 180
0% (autozero)
5%
36 months
up to 64 ports
Ion Mobility Spectrometry (IMS)
2
50
1
2
3 months
yes
Proton Transfer MS (PTR-MS)
30
250
< 1
< 180
0% (autozero)
5%
36 months
up to 64 ports
Ion Mobility Spectrometry (IMS)
5
50
1
2
3 months
yes
Proton Transfer MS (PTR-MS)
30
300
60
60
<2%
<2%
CO2
12 months
yes
Chemiluminescence CLD
30
250
< 1
< 20
0% (autozero)
5%
5
700
75
50
<0,1%
<0,1%
36 months 3 months
up to 64 ports yes
Ion Mobility Spectrometry (IMS) UV Absorption (UV-A)
120
250
< 10
< 60
0% (autozero)
5%
5
50
5
10
5
50
5
10
30
250
< 1
< 60
0% (autozero)
5%
5
50
5
10
5
50
5
10
30
250
< 1
< 60
0% (autozero)
5%
2
50
1
2
30
200
5
10
5
50
5
10
30
250
< 1
< 180
0% (autozero)
5%
2
50
1
2
5
50
1
2
2
50
1
2
5
50
5
10
30
200
5
10
2
50
1
2
2
50
5
10
2
50
1
2
2
50
5
10
2
50
1
2
2
50
5
10
36 months
3 months 3 months 36 months 3 months 3 months 36 months
3 months 3 months 3 months 36 months 3 months 3 months 3 months 3 months 3 months 3 months 3 months 3 months 3 months 3 months 3 months
up to 64 ports
yes yes up to 64 ports yes yes up to 64 ports
yes yes yes up to 64 ports yes yes yes yes yes yes yes yes yes yes yes
Photoionizsation Detector (PID)
Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS) Photoionizsation Detector (PID) Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS) Photoionizsation Detector (PID)
Proton Transfer MS (PTR-MS) Laser Induced IMS (L-IMS)
Proton Transfer MS (PTR-MS) Photoionizsation Detector (PID) Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS)
Laser Induced IMS (L-IMS) Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS)
30
250
< 1
30
250
< 1
20
700
120
30
250
< 1
2
50
1
1
1000
900
5000
900
30
250
< 1
1
501000
0.5
5
700
120
2
50
1
2
50
1
30
250
< 1
2
50
1
< 60
0% (autozero)
5%
< 60
0% (autozero)
5%
36 months 36 months
up to 64 ports up to 64 ports
Photoionizsation Detector (PID) Photoionizsation Detector (PID)
80 sec
2
900 < 20
1 80
2 2
2
<0,1%/month 0% (autozero)
0
0% (autozero) none
<0,1%/month
<0,1%/month 5%
5% <0,1%/month
0% (autozero)
5%
5% of NOx 2% of NOx
3 months 36 months
3 months no service required
1 month 36 months
3 months 3 months
3 months 3 months 36 months 3 months
yes up to 64 ports
yes Yes yes up to 64 ports yes yes
yes yes up to 64 ports yes
Converter/UV Fluorescence (UVF) Ion Mobility Spectrometry (IMS)
Selective Reactive Ion MS (SRI-MS) Continuous Wave - CRDS
Parallel-Wet-Plate Denuder/IC (PWPD-IC) Ion Mobility Spectrometry (IMS)
Switchable Reactive Ion MS (SRI-MS) UV Fluorescence (UVF)
Proton Transfer MS (PTR-MS) Proton Transfer MS (PTR-MS) Ion Mobility Spectrometry (IMS) Proton Transfer MS (PTR-MS)
A. Feilberg et.al. (2010) M. Takeuchi et.al. (2011)
D. Jaksch et.al. (2004) Warnecke et.al. (2003)
Methods and instruments are known and are being optimized Methods and instruments are known and in preparation for production
Methods and instruments are in beta tool status under qualification
Table YE4a
Supporting Table for On-line Methods (see Excel for more readable version)
Numerous studies related to AMC outgassing from the materials of construction of environmental enclosures and FOUPs have been performed to guide material selection for these enclosures. Beyond proper material choice the need for pumping and nitrogen purging of wafer environment enclosures is further investigated for critical process steps to diminish cross-over of contamination from different process steps by FOUPs. The potential for AMC to impact new processes should be considered in all process integration studies.
While not specifically mentioned, charged defects are also an area of concern where ion control is critical in areas such as Lithography particularly EUV. Wafer charging must also be managed to avoid attracting charged particles to the wafer.
This is specifically true where disruptive, revolutionary techniques are introduced into the manufacturing chain. For example, future lithography systems require vacuum processing and are not expected to impose new AMC control requirements in the clean room environment. However new challenge compounds are identified for the tool interior that may require novel air and purge gas treatments.
A detailed definition of critical impurities is provided at this link: 22AMC definitions.
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
Yield Enhancement 37
Temperature and humidity specifications have been added to Table YE3 this year for the most critical applications, e.g., lithography for several reasons.
1) The strictest requirements are driven by the lithography process, which is protected by an environmental chamber. The specifications in the Table YE3 reflect the inlet condition to each individual environmental chamber. Here especially, the maximum variation over time is important, which the environmental chamber must be able to compensate. At the POP lower specifications down to 0.03 K are maintained.
2) But also in the coater/developer track temperature and humidity specifications must be guaranteed to maintain stable conditions for the resist.
3) The temperature variation is also important for the stepper itself, since minor temperature variations can result due to different thermal extension coefficients in misalignments between the stepper foundation/wafer stage and the lens column. Steppers need up to a week to stabilize after a temperature change.
4) Another critical requirement is driven by metrology equipment which depend either on laser beams (the air density depend on temperature and humidity) and by measurements where misalignments are important.
The temperature and humidity stability over different locations within critical areas is less important. Also in other areas temperature and humidity variations shall be controlled to less strict limits since it may have an impact on the surface (native oxide formation) or alignments. Some companies choose not to have different specifications for critical and non-critical areas to allow flexibility in the cleanroom use as well as simplify the temperature and humidity control and the associated segregation.
These specifications are variational specifications and set points can be chosen in a wide range. A recent benchmarking study between fabs has shown values between 19.5 and 24C for temperature and values between 35% and 48% for the relative humidity. There are different drivers for establishing environmental conditions. The temperature set point is normally chosen based on comfort level and climatic conditions and the resulting energy consumption. The set point for relative humidity takes into consideration higher electrostatic charges at lower humidity and higher corrosion/native oxide formation at higher relative humidity. Capacity of AMC filters also depends on the humidity.
Another process area with temperature/humidity control as well as AMC control requirements is the location of the lithography excimer lasers, if they are installed in the subfab and not in the main cleanroom.
2.1.1. TABLE YE3 STRUCTURAL CHANGES FOR 2015 The revision of Table YE3 is taking into account the immediate wafer and masks environment and enclosures (FOUPs, reticle Pods). The revision aligns the table structure and content with actual manufacturing concepts involving clean room control, high purity storage environments as (bare) wafer and mask stockers and enclosures. Each process segment listed is split into information that is referring to the clean room ambient conditions and limits that are referring to the interior environment and atmosphere of FOUPs, reticle Pods or bare material storage environment. Clean room ambient conditions are regarded as POE conditions to critical process steps that may involve further tool related measures of AMC protection and reduction, yet require controlled entry conditions to achieve proper process control. FOUP and reticle Pods interior limits are not only influenced by clean room environmental contamination but are depending heavily on remaining active material outgassing or re-evaporation of AMC attached to the containment walls. Other structure changes are as follows:
For reasons of transparency and comparability process limits for clean room environment and containments (FOUPs and reticle Pods) are posted side-by-side per process.
THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS 2.0: 2015
38 Yield Enhancement
The revision of AMC limits in Table YE3 performed in 2011 has been based on a structured investigation and inquiry process that involved front-end manufacturing companies, institutes and academia, and included their published information on defects and yield.
The deduced tabulated recommendations for AMC limits consider integrated concepts of clean room limits and wafer/reticle environment limits at actual standard sit times or operation and service times for materials and tools that are regarded as acceptable under yield requirements and factory integration processes.
Example of Tabulated Values in Table YE3:
Gate/Furnace Area Wafer Environment (Cleanroom FOUP Ambient/Tool Ambient) Total Metals [A] (E+10) Dopants [B] (E+10, front end of line only) Volatile Organics (w/ CGMS retention times benzene, calibrated to hexadecane) [C]
< 10 atm/cm2/week < 10 atm/cm2/week
20,000
Gate/Furnace Area Wafer Environment ( FOUP Inside)
Total Metals [A] (E+10)
Dopants [B] (E+10, front end of line only)
Volatile Organics (w/ CGMS retention times benzene, calibrated to hexadecane) [C] SMC organics on wafers, ng/cm2/day [D] Total SM on wafer, E+10 atoms/cm2/day
SMC--surface molecular condensable, SM--surface metals
< 0.5 atm/cm2 < 0.5 atm/cm2
20,000
NA < 0.5 atm/cm2
[A] Detection of metals at the levels indicated will be dependent on sampling time and flow rate. Sticking Coefficients vary widely for metals. It is generally believed that Cu has a sticking coefficient 10x of other metals, and therefore the guideline for Cu could be lower.
[B] Includes P, B, As, Sb
[C] Ideally, continuous monitoring using online instrumentation would be preferred when practical since this can give both long term averages and catch excursions. When online monitoring is not available, an average grab sample for at least 4 hours, and not more than 24 hours is recommended, to get an average, increase sensitivity of the analysis, and avoid short term transient effects
[D] SMC Organics: Single wafer shall be oxidized to make organic-free, then wafer shall be exposed for 24 hours and top side analyzed by TD-GC-MS with 400C thermal desorption, and quantitation based on hexadecane external standard. TIC response factor per SEMI MF 1982-1103 (formerly ASTM 1982-99).[4] Limits determined by above method are a guideline for many organics. Note higher limits can be used for process wafers oxidized or cleaned prior to subsequent process step. Processes such as gate oxide formation, or polysilicon deposition, may be more sensitive to organics, especially high boilers such as DOP. Silicon nitride nucleation may also be more sensitive than above for some processes. Please note dopants requirement is covered in earlier section. Contamination levels are time based, and samples should be exposed for a weeks time for better sensitivity; ng/cm2/week. Total contamination level on reticles that cause problems also vary with energy exposure. These guidelines subject to change with new data currently being generated.
The structure and tabulated values in Table YE3 (process segment Furnace/thermal treatment): AMC limits for clean room ambient environmental control are listed side-by-side with AMC limits recommended for the wafer environment inside FOUPs. Tabulated values are derived from front-end manufacturing defect analysis and scientific work of academia.
New line item in Table YE3: Moisture: In order to reflect the impact of moisture to the wafer- and reticle environment, moisture has been introduced as additional line item to Table YE3, starting with "exposed copper".
2.1.2. NEW AMC TOPICS RELATED TO FACTORY INTEGRATION (AMC INTEGRATED CONCEPT)
The FOUP is a plastic container that stores and carry 25 wafers from tool to tool. During storage, wafers may outgas chemicals and by-products of previous processes inside the FOUPs. As a consequence, the concentration of some critical AMC inside FOUPs may be higher than inside the cleanroom by several orders of magnitude.
The FOUP itself may be a source of contamination because of residues from its own manufacturing process, and also because it can trap AMC coming from contaminated wafers which will then be further outgassed. The defects due to AMC are a result of a combination of critical contamination inside the FOUP, type of substrate
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and storage time. Some defects are also linked with humidity and temperature conditions. As a result, the measurement and control of the contamination inside FOUPs are key challenges for the IDMs and foundries.
Witness wafers have been used to link surface molecular contaminant (SMC) concentrations to specific defects. The surface concentrations are usually expressed in a maximum allowable number of molecules/cm2. Sticking coefficients (s) for different molecules are found in the literature and help us to relate SMC to AMC concentrations in the air. AMC concentrations which will generate surface defects on the wafer are also depending on time of exposure at a given humidity and temperature. The general formula relating SMC to AMC is as follows: C = N / (sVt), where C is the AMC concentration in the air, N the SMC concentration on the wafer, s the sticking coefficient, V the mean speed of the AMC and t the exposure time. The YE3 table is reporting recommended AMC concentrations in ppt(v) for 24 hours exposure time inside FOUPs. For lower exposure times, new AMC values can be calculated using the formula above. A simple consequence is that the allowable concentrations in air are higher for shorter exposures (linear relationship according to this equation). Sticking coefficient are not strictly constant for different exposure times and the approach above only represent a simplified version of a more advanced theory using the kinetic laws of contamination (more details can be found in the literature).
The Yield Enhancement group has been working on the different issues related to FOUP contamination and therefore proposes a new table describing the potential solutions. Factory Integration is dealing with the whole process flow including: cycle time, q-time constraints, layout and consumption. As a consequence the integration of the measurement and control of contamination inside FOUPs was handled as a common project between YE and FI. In the frame of this common work, Factory Integration has the role to evaluate the validity of each solution in regards to cycle time and throughput. FOUP cleaning is increasingly more important to mitigate the FOUP contamination particularly from pores due to outgassing from the wafers. This can be mitigated by using a FOUP with lower porosity and more frequent FOUP swap and subsequently cleaning the FOUP before reintroduction into production.
In 2011, YE defined the potential solutions for the following 3 main topics:
- Outgassing of new FOUP - Outgassing of "in production" FOUP - Cross-contamination on wafers inside FOUP
2.1.3. NEW AMC TOPICS RELATED TO 450 MM There are several considerations for critical contamination control specifications (CCCS) for the clean room environment and wafer environment in 450 mm wafer sub 1 nm technical node high volume manufacturing.
A transition in production from 300 mm wafer substrate to 450 mm diameter substrates is driven by output per wafer and time and therefore by cost. Yield loss would affect the overall output of the 450 mm production line which is subjected to be more productive than current 300 mm lines. Consequently this would affect the return on investment (ROI) on 450 mm investments which are right now assumed to be wafer diameter specific and therefore comparatively massive.
Critical contamination control specifications for the wafer level have to be put forward as projections for 450 mm wafer size together with the sub 1 nm node. Current know-how and information on wafer processing speed, wafer defect budget, handling modes and foreseeable fab space structure have to be taken into account. From this information CCCS for the clean room environment and the wafer environment need to be derived.
Contamination control specifications for the production of sub 1 nm structured chips products on 450 mm wafers experience in some parts influences that come with the technical node and materials used. Other parts are influenced by the projected influences from wafer size and possible countermeasures.
Based on know-how from current 300 mm high volume manufacturing (HVM) at 28 nm node in some segments, conservative, steady projections of the requirements can be proposed for specification. Such steady
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specification for the clean room environmental level can often only be maintained due to permanent technical improvements and active contamination control (counter) measures on the tool level. Such examples for foreseeable unchanged specifications on the clean room level are the specifications for the following:
Vibration--The mere increase in wafer size would pose significant challenges with regard to wafer handling due to higher masses of tool structures, lower stiffness and an unwanted reduction in resonance frequency. This shift - if not actively addressed - could increase the risk of coupling of natural background into the tool operation. Yet the actual perspective is that 450 mm production could further be possible in clean rooms respecting vibration class VC-D supported by active vibration control on tool-level
Particle cleanliness--Despites the model-related shrinking of the critical particle diameter together the shrinking of the line structures there is little evidence that significant tighter requirements for particle cleanliness in the clean room environment (class 4 or class 5 to ISO 14644-1) or mini-environments (class 1 to ISO 14644-1) would come along with the introduction of 450 mm wafers. Uncertainties exist based on the expected broad implementation of FOUP purge with XCDA or dry nitrogen that could enhance ESA (electrostatic attraction) based on increased surface charges.
For two contamination categories tighter specifications are foreseeable which are mainly due to the technological node expected on the onset of 450 mm production
ESD--The requirements to prevent ESD (Electrostatic discharge) induced defects will get more stringent with reduced line width but are supported by active countermeasures on the tool side
EMI--It can be expected that EMI (Electromagnetic interference) will gain more attention and may need enhanced preventive action. This is mainly related to the expectation that for sub 1x nm node both e-beam and TEMS may become production relevant tools thus requiring that standard production floor space may be capable to accommodate such EMI-sensitive tools
AMC--In the case of AMC (Airborne molecular Contamination) an alignment of requirements for various tools sharing the same fab space and experiencing the same threat to wafer yield should result in a simplification of the contamination control model and a higher ability to achieve yield safely. Currently AMC control strategies for the different processes vary widely based on the preparedness or unpreparedness of the tools for non-ideal contamination situations of the clean room environment. This leads to relaxed clean room environmental standards in case tools come with a well-defined AMC protective interface and stringent requirements if the tools arrives unprepared creating either a demand to adapt the clean room condition or the minienvironments conditions.
Considering that AMC effects to wafers do generally not originate from concentrations but form doses related to sit-times the migration to 450 mm wafers can have an impact on the contamination burden if processing speed would not scale up proportional to wafer size. Currently the WECC group would expect this effect to be most pronounced for metrology tools. The progress on processing speed needs to be monitored to decide whether AMC control limits for WECC would need scaling in the coming years due to the wafer size effect.
2.1.4. NEW AMC TOPICS RELATED TO INTERACTIONS OF AIR IONIZERS WITH AMC Corona based air ionizers may be used to neutralize charge to prevent electrostatic discharge damage and electrostatic particle attraction to wafers, masks or other surfaces.
The hot emitter tip, UV light, energetic electrons and ions formed can interact with AMC's (Airborne Molecular Contaminants) that have Si, S, P, B, Cl, Sn or other selected elements to make nm non-volatile particles such as oxides, and larger deposits or dendrites on the tips up to millimeters, that can throw the ionizer out of balance or lead to ionizer faults. While presumably rare, if this happens, the deposits call attention to the unusual presence of specific excess AMC's that can react with also with other energy sources to, not only deposit onto ionizer tips, but possibly onto other surfaces, due to interaction with excess energy such as 193nm lithography, lasers and inspection tools or hot surfaces. The compounds might degrade optics, masks, scanners, or other surfaces. Analysis of the ionizer tip deposits by SEM-EDS, ICP-MS (especially for boron) or other methods can indicate what elements are present in air, aiding selection of methods to look for possible sources of a limited number of contaminants, instead of large sections of the periodic table. This
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method can be used to more rapidly find some AMC issues for which no other test are currently available, such as ppbv and higher leaks of some hydrides, silicones, silanols, halogens, organometallics, O=C=S, TEOS, organophosphates, ammonia, acids, etc.
Process critical materials--Additional experimental investigation is required to support our understanding of impurity specifications in novel materials, such as Cu plating solutions, CMP slurries, or chemical vapor deposition (CVD) precursors to high/low- dielectrics and other thin film materials. For many years the critical particle size concept was used to judge whether particles will have an impact on yield or not. This concept has to be rethought since particles do not impact the process yield alone by their physical size but also by their chemical composition. The allowable particle concentration thereby depend also on product parameters such as cell size and have therefore been aligned with the particle concentration on the surface as derived by the Front End Processes (FEP) TWG surface preparation group calculation model.
2.1.5. ULTRAPURE WATER QUALITY
Ultrapure water--UPW is purified water with most of the quality parameters below or near their detection limits of the most advanced metrology. Specific definitions of the water quality requirements to enable future technology are presented in the Table YE3. Particle levels are reduced using the best available ultra-filtration (UF) technology, but today's particle counting technology is not able to keep up with critical particle node due to continued scaling of critical semiconductor devices. . Lack of proven particle metrology limits the ability to confirm whether UF is effective in controlling killer size particles down to the critical particle size referenced in table YE3.
It is important to remind that the roadmap is focused on technology enabling, identifying the parameters that require new technologies for monitoring and control. For the practical purposes, SEMI F063 provides a guide that can be used as a reference specification for the UPW quality in design and operation of advanced semiconductor processes, considering feasibility of the existing technologies. More stringent criteria beyond 2015 are only projected where there is evidence that manufacturing process requirements demand improvements. UPW is generally the cleanest fluid available in the manufacturing process. As such there is only selective data currently available correlating contamination level and device yield.. For this reason the UPW Roadmap for contamination tolerance is relatively stable over time. Over the past several years the UPW and Chemical groups have worked closely together to develop a failure mode and effect analysis (FMEA) to evaluate the risk of known contaminants of the wafer.
The UPW section of Table YE3 considers some parameters as process variables rather than contaminants. It is clear that the stability of the wafer processing environment can be as important as the level of contaminants present for some parameters. For example; some semiconductor manufactures treat dissolved oxygen (DO2) in this way, while others consider it a contaminant. Stability of temperature continues to be important for immersion lithography.
For 2015 some commonly monitored parameters such as resistivity and bacteria are not included in the table, as they do not represent technology challenge and only used for monitoring operational performance of the UPW systems. These parameters are critical for the water quality, but non-critical for the future technology enabling. Bacteria can be controlled down to zero level and the resistivity became non-sensitive to the water quality variation within the ranges targeted for the ionic species in UPW.
UPW parameters were reviewed for the 2015 roadmap for the specific location where they are critical to maintaining semiconductor yield. The notes to the Table YE3 contain definitions for these parameters. Some parameters are specified for POP (Point of Process), while the others are specified in different locations. The definitions are driven by the consideration of whether the tool environment and measurement location may affect those parameter values
2.1.5.1.
PARTICLE CONTAMINATION IN UPW
The focus will turn more to critical parameters such as particles, metals, and organic compounds. Particles remain a high and growing risk, critical for implementing future semiconductor technology; due to its high sensitivity to reducing line widths.. On-line metrology for particles in liquid does not address killer particle size, and therefore, filtration efficiency for killer particles provides limited information.. At the same time it is
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apparent that the killer size of the particles has approached filtration capability of the most advanced final filters, while there is some test data suggesting the particle challenge concentrations to the final filters from UPW system components can be very high. (Refer to ion exchange particle shedding data in the published supporting materials).
The 2015 edition includes specifically a category for the particles in EUV mask operation. This is to emphasize the importance of the particle control specific to this area. Electrically active particles (mostly metallic) were removed from the table based on feedback from FEP, suggesting that all particles are equally critical to future technology. The colloidal silica parameter has been removed from the table. Colloidal silica will now be considered as a particle, subject to the particle specification in the table. If colloidal silica particles are controlled to the particles specification, all measurable silica in UPW will be in the form of dissolved. Hence the value for a total silica specification remains (total silica = dissolved/reactive silica). Reactive silica concentration is limited due to its negative impact on device yield, forming water marks on the wafer. In this case, reactive silica specification can be measured using either total silica analyses methods (i.e., ICP-MS) or as reactive silica (by colorimetric method) to the level specified in the table. For practical purposes, measuring total and reactive silica may be considered to confirm no presence of colloidal silica. As a work around to the particle metrology gap, the UPW forum has worked with SEMI to develop a filter performance validation standard (SEMI C079) as a risk mitigation measure. We are continuing to investigate selective defect density in the critical areas that require better understanding. This includes particle deposition modeling based on a thorough literature review and experimental data. Experimental data is included in supplemental materials.
2.1.5.2.
METAL CONTAMINATION IN UPW
The UPW team is currently reviewing previous categorizing critical as 1ppt and non-critical metals as 10 ppt). This is based on the fact the concentration of metal on the wafer is function of UPW concentration and deposition ability' Instead we are considering defining the UPW spec based on device impact (XE+Y at/cm2) and deposition as a function of metal concentration in the bulk liquid. We propose the target levels based on the device impact and the deposition efficiency.. We have updated the FMEA accordingly and suggested maximum concentration of metals with changes based on our calculation.
Organic Contamination in UPW
There has been an increased interest in the past few years to understand how organic contamination of UPW may affect semiconductor devices. Organic contamination is currently measured in terms of its total organic carbon content or TOC. This measurement of the organic content does not account for the type of organic and how it may react with various wafer surfaces or how the reaction may impact device yield. As a result of this, the ITRS UPW team removed TOC from the table in the 2013 publication. In place of TOC we are now categorizing organic compounds in UPW for critical and non-critical based on their boiling point. Immersion lithography lens hazing was previously a driver of UPW TOC<1.0ppb.
The 2015 Yield roadmap maintains a separate line for immersion litho TOC (<1.0 ppb), implying that this may be required as POU definition, while the rest of the water quality spec was relaxed to 3 ppb of non-critical organics. We continue working on a new definition of critical organics, based polar strength as quantified using boiling point. The definition of the critical organics was included in the table notes, which recommend end users to consider characterization of the UPW organics in their own specs. New metrology is needed for on-line detection of the critical organics.
Critical Organics - non-volatile polar organic compounds with boiling point > 200C o Critical organic compounds should be controlled to < 1 ppb
o Organic compounds are categorized as critical with respect to its ability to form a hydrogen bond with
any oxide surfaces including gate, tunnel, or native oxide
o Total non-critical organic compounds should be controlled to < 3 ppb o Non- Polar Organics - have very little attractive strength to have any direct device impact. Non-polar
organics may adhere to a hydrophobic wafer surface as foreign material (FM) via VanderWaals forces which are relatively weak and are easily removed in chemical cleans.
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Critical carbon atoms on wafer related to TOC in bulk fluid o Defined by FEP as 1xE-12 atoms/cm2 for Si-C defect in furnace. o Breakdown of organic compounds particulary at higher temperature (>200 C) is an important consideration for the formation of Si-C defect. The level proposed is considered to be adequate to mitigate such risk of such defect formation. o Critical boiling point of organic compounds defined by FEP as 200oC o UPW ITRS group is looking at compounds with lower boiling point that may be related to other defects
We continue to use failure mode effects analysis (FMEA) approach to determine the overall risk of each subgroup to the wafer manufacturing process. In 2013 the UPW team completed an organic speciation benchmarking study which used LC-OCD analysis to speciate organic compounds in UPW used at ten advanced technology facilities. This information is available as supporting documents and will give us baseline data to identify typical organic compounds in semiconductor UPW systems and can be used for occurrence risk factor in the FMEA review.
It is critical that further experimental analysis is completed in the next few years to determine the correlation between failures in the semiconductor devices and level/type of organic contaminant. Research will continue in 2016 to investigate this further.
UPW measurement methodologies--General test methodologies for monitoring contaminants in UPW are indicated in the Figure YE2 below. Over the past few years the ITRS UPW team has benchmarked many advanced UPW systems to determine water quality. Past benchmark efforts have identified the inadequacy of some measurement methodologies to quantify contaminants in the UPW. Sensitivity of the following methods is presently adequate: viable bacteria, dissolved gasses, ions, total organic, and metals. While particle measurement is not adequately sensitive to validate quality at the critical dimension it continues to be a valuable tool to detect filtration failures.
Parameter TOC Organic ions Other organics Total silica Reactive Silica Particle monitoring Particle count/characterization Cations, anions, metals Dissolved O2 Dissolved N2
Measured (POD/POC) Online Lab Lab Lab Lab Online Lab Lab Online Online
Test Method Conductivity/CO2 Ion chromatography LC-MS, GC-MS, LC-OCD ICP-MS or GFAAS Colorimetry Light scatter SEM--capture filter at various pore sizes Ion chromatography, ICP-MS Electric cell
Electric cell
ICP-MS--inductively coupled plasma mass spectrometry GFAAS--graphite furnace atomic absorption spectrometry SEM - scanning electron microscope
Figure YE2 General Test Methodology for Ultrapure Water
UPW and liquid chemicals particle measurement--Problem Definition and Goals: The sensitivity limit of particle counters for UPW and liquid chemicals has not kept pace with critical particle size (the size of particles which are thought to be detrimental to wafer yield). Although this concept needs to be discussed again since particles not only impact yield because of their physical dimensions, but even more by the chemical composition, e.g., as spot Fe contamination. Measurements of these nanoparticles are made difficult by the low scattering efficiency of them. Low particle concentrations and small sample volumes of current
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particle monitors can result in large sample-to-sample variability. More sensitive particle measurement methodology with adequate measurement statistics is needed to meet projected purity goals.
2.1.6. THE SENSITIVITY PROBLEM
As of 2015, the highest sensitivity particles counter commercially available for both UPW and liquid chemicals is 0.02 microns. Even at this size the detection efficiency is only 2-5%, so most particles at 0.02 microns and smaller go undetected.. Experiments have shown that small particles may even deposit preferentially [M. Knotter] and therefore the impact is increased even further. Improvements in particle counter sensitivity for UPW have been accomplished by increases in laser power. While improvements in sensitivity for liquid chemical particle counters are viable. Further sensitivity improvements for UPW using this approach are unlikely, due to the significant cost implications. There is an ongoing effort to develop alternative technologies the optically based particle counters To estimate the concentration of smaller particles in chemicals currently an extrapolation assumes a 1/d3 relationship between particle counts and particle size in liquid chemicals. The further away the particle size of interest gets from actual measurement capabilities, the higher the potential for error-error being defined as the difference in the projected value compared to the true value. Moreover, the power law coefficient may be significantly affected by the actual filtration capability of the final filters used upstream to the particle measurement, making projections impossible. Therefore, it is important for the industry to develop a more sensitive method that can measure particle concentrations at greater sensitivity to validate the particle count versus particle size relationship so that the relationship can continue to be reliably used. Further discussion is needed on validity of the power law extrapolation, e.g., effect of filtration on extrapolation (filter rating/detection size).
2.1.7. THE MEASUREMENT PRECISION PROBLEM:
Statistical process control is increasingly being used to monitor the consistency of process parameters. Process variation of fluid purity can be as critical to wafer yield as the absolute purity of the fluids. Therefore, it is important that measurement methods detect sufficient number of events to ensure confidence in measured particle concentrations. Development of other statistically significant particle counting methods or a higher sample volume particle counter is needed to improve confidence in reported particle counts. The sample volume (volume of fluid measured) will determine the number of particle counts that are detected during the sample interval. Follow this link for more details on particle monitoring.
Although the gas/liquid chemical section of Table YE3 shows an essentially flat purity trend, there is likelihood that specific process steps may require higher purity. In some cases, yield improvements may be achieved more by reducing variations in purity than by reduction of average contamination levels. Hence, there is a need for improved statistical process control of contamination levels during manufacturing and delivery of these process materials. In 2008, SEMI released the results of a comprehensive effort to create a standard set of guidelines for defining "in control" specialty gases [1]. A coincident effort by several large semiconductor manufacturers began for the purchase of selected specialty gases. Although the number of companies that have started utilizing in control guidelines for the purchase of consumable raw materials has increased, along with the breadth of the offering for in control materials, however, the industry has not yet settled on one standard set of criteria. Overview for gases and liquid chemicals--The recommended contaminant values for gases and chemicals in Table YE3 represent typical gas/liquid chemical quality requirements at the point of entry to the process tool (POE) for the more demanding manufacturing processes in the roadmap. In many applications, the requirements for the contaminants in these gases and/or liquid chemicals may be relaxed as dictated by the specific process requirements. On the other hand, some manufacturers have claimed benefits from lower contaminant levels. Considering that a given process can be run successfully within a "window" defined by a range of material purity and also by ranges in other parameters (purging time, etc.), it follows that, in practice, trade-offs exist between imposed purity requirements, process throughput, etc. Pushing a process to the upper limit of its "purity window" may require significant investment of time and effort in optimizing other parameters, and the economics of pursuing that effort will depend on the environment. It may also be that benefits attributed to low contaminant levels are more attributable to the reduction in contaminant variations
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achieved with high-purity process gases and chemicals. This topic is addressed in more detail below regarding the push for the adoption of statistical process control, SPC, for specifying process fluid purity.
There are three primary sources of process environment contamination: One is the impurities in the process materials as supplied. The second is the delivery system or the process itself. The third is decomposition, which may be caused thermally or by reaction with adventitious contaminants e.g., moisture. These contamination sources are found throughout the pathway from the delivered gas or chemical to the wafer surface. Table YE1 describes the several interfacial points of process materials with equipment found along these paths and associates them with the various TWGs within the ITRS and other organizations such as SEMI that focuses on them. This helps to clarify the relationship of these organizations with the WECC while also removing ambiguity about the definition of various points along the process path.
While purity measurements at the Point of Process, POP (that is, in the processing chamber itself), would provide the most direct correlation between gas or liquid quality and process performance, these measurements are often very difficult to obtain with the exception of certain fluid properties in wafer immersion baths. Examples include both particulate generation during plasma processes and wafer out gassing. The latter is the most important source of water vapor contamination in many processes, often obscuring moisture contributions from the process fluid. Measurements at the POU provide the most direct information of the quality of process fluids going directly into the process chamber, but these are also not available for many of the common processes.
Because of these difficulties, the values in Table YE3 are intended to represent those at the Point of Entry, POE, defined as the inlet to the process tool as described in Table YE1. There are sufficient measurement data on bulk gases and aqueous fluids to provide guidance with regard to POE impurity levels for many applications, although measurements on these fluids are often performed at the POS, POD, or POC. For these materials, which are relatively unreactive and delivered in large volume, the extrapolation to POE is generally very reasonable. In the case of Specialty Gases and other reactive process fluids, such extrapolation is more delicate because delivered volumes are smaller, increasing sensitivity to contamination effects, and degradation in the distribution system related to materials of construction, atmospheric contamination, thermal degradation, etc. is more likely. These factors are minimized with normal best construction and operations practices, and therefore the best guidance available is often regarding POS specification and to a lesser extent POD or POC measurements, which are interpreted as equivalent to POE. In summary, while the intention is to recommend POE purity levels for all gases and liquids, in practice, the supporting data has more often been collected at POS, POD, or POC.
The targeted levels can be reached either by bulk delivery of a fluid with requisite purity or through use of a local purification/filtration. Care should be taken, at a minimum, to maintain the quality of the gas coming from the source, ensuring that contamination is not added downstream of the POS, as may occur due to particle generation at components, moisture out gassing, byproduct generation due to incompatible materials, etc. Particle filtration as close to the POU as possible is generally advisable for gases. For the most critical applications a local purifier may be used to enhance or ensure ultimate purity at the POU. In those cases, the prevailing approach is to seek POC levels that are adequate for the process and to view the purifier as "insurance." The challenge to the purifier is minimal, and long purifier lifetimes can normally be expected.
An important exception to this guidance is for some specialty materials that undergo a variation in composition as they are distilled from the cylinder or other delivery vessel in a bulk vapor delivery set up. Anhydrous HCl for example is known to form very stable hydrates with water that results in concentration in the water content in the cylinder as the original specified contents are removed. In this case a combination of rigid specifications on how much of the contents can be used before moisture becomes unacceptable and the application of moisture gettering purification devices somewhere in the vapor transport path. Liquid anhydrous ammonia are another specialty gas with this potential issue [3], Within the realm of relatively volatile liquids that are delivered in bulk, i.e., not by direct liquid injection, volatilization,, aqueous hydrogen peroxide, aqueous ammonia and likely many of the amide based CVD/ALD precursors are expected to undergo similar distillative variation and/or thermal degradation under delivery conditions [4], Depending upon the process
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sensitivity this might be a source of poor film quality or process variability that can be addressed by attention to the delivery method or the application of POUP .
Point of use purifiers and filtration units are finding application in newer atomic layer deposition techniques, ALD, for example where the films are deposited by the monolayer and incorporated impurities can be especially destructive. A near/medium term challenge is filtration of the precursor vapor. The sources can be sublimable solids or readily condensable vapors of low volatility liquids. These can resolidify or reliquify causing plugging and instability in fluid transfer to the substrate surface. In addition, these vapor delivery systems are typically low pressure (< 100 Torr) which can change the fluid dynamics and hence filtration efficiency dramatically. One additional limitation with the POUP systems in particular is endpoint monitoring to determine when the purifier matrix is exhausted. Practically this is handled by routine change out of the purifier units at a frequency that typically results in no problems.
Specific purity challenges will be discussed below, but generally there is little objective evidence to suggest that the purity levels listed in Table YE3 are not suitable for multiple generations of semiconductor manufacturing. Yield improvements are expected to be achieved by reducing variations in purity. Statistical process control (SPC) on incoming materials will reduce variation at the POS. Inconsistencies at the POU may remain due to variations in downstream contributions, e.g., when the flow in a distribution system is decreased, moisture contamination due to out gassing tends to increase. Elimination of these variations may again require purification at the appropriate point (e.g., POU purification, POUP).
Bulk and Specialty Gases--The major bulk gases are listed separately in Table YE3. The 2007 roadmap had indicated an increase in purity requirements post 45 nm. This type of improvement might be anticipated, based upon historical trends as design rules tightened, but there is again little objective evidence to support the need for improvements across the range of bulk gases. Informal poling of several large semiconductor manufacturing organizations suggests that an increase above current purity requirements for the majority of bulk gases is not necessary to meet post 45 nm design rule manufacturing. For very special applications where extraordinarily higher purities are critical, special purity grades or additional purification will be required. As exemplified above, downstream POUP might also be utilized as an additional means of removing variability in POS gases. Therefore, Table YE3 has been modified from 2005 to remove many of the step improvements scheduled for future manufacturing nodes except where specific information has been identified to justify the change.
The situation is similar for many of the Specialty Gases, although several additional categories of applications have been added to better identify needs for specific processes, e.g., etch, deposition, doping and laser applications. Like the Bulk gases, the values in Table YE3 have been left at current levels, unless an objective justification for increased purity can be identified. Although changes to the current Table YE3 values for gases are small, the introduction of so many new materials and the process innovations required to meet future design rules, e.g., atomic layer deposition, will require close monitoring. More details with regard to bulk and specialty gases are provided in the gas supplemental documents.
Statistical process control for process gases and liquids was implemented circa 2005 by large semiconductor manufacturer for a selection of critical process fluids, e.g., TEOS. Rather than simply meeting specification values for a set of quality control parameters, the materials were selectedagainst specifications dictated by statistical control of variability of the materials. The utilization of SPC selection criteria continues and has expanded, however, there are still no standards accepted across the industry that define the SPC process.
The promise of providing "in control" process fluids is anticipated to improve process yields by either minimizing the overall variability of the manufacturing process or in simply reducing the likelihood of a process crash resulting from large variations in material quality that would still nominally have met a more standard specification.
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An informal survey of several large semiconductor manufacturing companies on their implementation of statistical process control requirements for their bulk and specialty gas purchases indicates that SPC processes are already being applied to many of the materials utilized in manufacturing, or will be shortly. However, the criteria that form the basis of "in control" varies substantially. Survey responses suggest that customer expectation is that the application of process control for the preparation of POS materials will improve their semiconductor manufacturing process stability and are critical for high yield manufacturing. Initial implementation, will likely focus on specialty gases that exhibit the greatest potential for causing semiconductor process variability, e.g., anhydrous HCl but will be used on new and existing products for both memory and microprocessors.
Liquid chemicals--Table YE3 summarizes the purity requirements for liquid chemicals delivered to process tools. Pre-diffusion cleaning and EUV mask blank cleaning requirements drive the most aggressive impurity levels. Liquid particle level targets are shown to become purer each technology generation. These target values are derived from the purity requirements on a wafer as calculated by the FEP surface preparation group assuming a linear relationship between the concentration in the liquid and on the wafer. Particle counters currently are capable of measuring only to 40 nm for liquid chemicals. By assuming a particle size distribution, it should be possible to infer particle concentrations to smaller particle sizes, but this will be influenced by the level of filtration utilized. Another measurement challenge for several chemicals is the differentiation between particles and bubbles, which is currently not possible.
The ability to accurately analyze organic, anion, and cation contamination in process chemicals is becoming more critical to successful wafer processing. In the supplementary links an 23ion table and a mixing calculation are provided that show for which chemicals which ions are important and in which chemicals they could actually occur/have been observed. With the increased use of CMP and plating chemicals, there must be a better understanding of purity requirements for the delivered chemicals.
ALD/CVD Precursors: At recent nodes Atomic Layer Deposition (ALD) processes have been adopted aggressively and that proliferation is expected to accelerate in the future. ALD processes will therefore constitute a growing subset of the processes used in HVM and some discussion of common/unique aspects of ALD processes with respect to Wafer and Environmental Contamination Control (WECC) is warranted.
For the vast majority of semiconductor processes, gaseous reactants are delivered to the processing chamber at atmospheric or superatmospheric pressures. However, for most ALD processes, the precursor is delivered at pressures typically in the range of 5 Torr to 100 Torr to the reactor, which is processing typically below <1 Torr. To minimize precursor deposition/condensation within a delivery system, the equipment is typically heated to 100C or greater. At such conditions, the gas flow through many of the delivery system subcomponents is in the slip flow regime. In the slip flow regime, there is a non-zero boundary velocity at solid surfaces and a thinner boundary layer. This significantly alters both the fluid dynamics and heat transfer properties of the system. Additionally, ALD precursors can readily form particles in the precursor delivery system through both condensation and reaction with residual oxygen-containing species. With solid precursor sources, there is an added risk that source material particulate can be entrained by the carrier gas.
Furthermore, metallic impurities in inorganic, metalorganic, organometallic or organometalloid precursors are typically orders of magnitude higher in concentration than in most non-metal containing gas streams and can be a source of metallic contamination in the resulting films. In addition, thermal decomposition of precursors on the wafer or in the gas phase can produce particles, or provide another source of in-film contamination. OEMs and precursor suppliers should keep these complexities in mind when designing or modifying precursor delivery sub-components and systems. Semiconductor manufacturers should consult with their suppliers if they are interested in re-engineering or adapting their precursor delivery systems since changing the pressure drop or flow dynamics of a vapor delivery system for a sensitive precursor may have unintended negative consequences.
Due to the low vapor pressure of many ALD precursors the process canisters are usually kept at elevated temperature (>90C) at the point of use in the tool gas box. Many ALD precursors will have a slow rate of
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48 Yield Enhancement
decomposition at these temperatures and extra care should be taken to adjust the size of the on board source canister to consume the source before process deteriorating decomposition starts. In many cases smaller heated onboard source canister that is refilled by a bulk deliver system or a liquid injection system without tank are preferred solutions.
When supplying the precursor from a bulk delivery system in the sub fab extra care should be taken to avoid release of bubbles from the push gas into the liquid precursor. The bubbles are released due to the pressure drop going from the point of push gas insertion (sub fab) up to the tool. These bubbles will typically disturb the liquid flow controllers in the tool gas box or direct liquid injection systems resulting in a disturbed fluctuating delivery flow of precursor into the reaction chamber and possible particle generation in the injection system if the injection is over flown with precursor above it is optimal working conditions. Down stream of the ALD reactor, the relatively low vapor pressure ALD precursors and process by-products tend to condensate at first point of temperature drop. Therefore the pump stack and pressure control should be heated above the condensation temperature and all the way to preferably a cold trap that condensate the precursor in a controlled manner to avoid back streaming particles into the reactor. Finally, semiconductor manufacturers should conduct due diligence audits of any analytical methods or techniques used to screen precursor quality with the understanding that many of the possible errors made while analyzing the precursors (e.g. incomplete digestion, failing to account for sample matrix effects, etc.) can lead to results that under-report the true impurity level. Many manufacturers are adopting ship to control standards individually with their suppliers in order to minimize any precursor variation associated yield loss in their factories. Table YE3 contains information only for very few CVD/ALD precursors. The variety of layers and the respective contaminants is enormous.
Therefore, a link to the precursor table is provided. The precursor table provides information by application as to which precursors are potential candidates at different technology generations, and the nature of contamination that can be expected. A major challenge is the development of accelerated yield learning for critical processes that introduce new precursors that will only be used for one or two generations.
Bulk/specialty gases--There were only a few changes to the bulk gas purity requirements. The measurement of organic refractory components at <0.1 ppb is a detect ability challenge for both nitrogen and helium used in lithography applications. The roadmap indicates these areas as orange from 2007 to 2010 because this is at the limit of detection for current analytical methods.
In addition, changes were made to better delineate the need to control Ar as an impurity. The N2 specification was changed to eliminate Ar as a critical impurity, although it was left in the O2 specification. Even so, the 50 ppbv limit given in 2005 was raised to an Ar limit of <1000 ppbv. The ongoing requirement in O2 derives from the potential for uncontrolled Ar impurities to impact plasma etching processes, although typical Ar specifications for O2 used for etching is more consistent with the <1000 ppbv level.
For some processes, such as advanced lithography, very small quantities of "high molecular weight/high boiling point" (e.g., C6-C30) hydrocarbons are detrimental because of increased adherence to the exposed surfaces, and potential for photochemical degradation to leave non-volatile residues on lenses, masks, mirrors, etc. However, any organics, even ones with retention times less than C6 are considered detrimental if they can result in refractory deposits. For the same reason, other potential impurities such as siloxanes or organophosphates can also be very detrimental in extremely small quantities. In order to detect such species with ultimate sensitivity, it is necessary to directly detect the relevant species and calibrate the analyzer with the appropriate standard. The methods used are analogous to those for AMC, such as TD gas chromatography (GC)/mass spectroscopy (MS) (TD = thermal desorption) or TD GC/FID, or ion mobility spectroscopy (IMS). Even these approaches may miss some heavier hydrocarbons and/or polar species that tend to remain in the column or emerge as very broad peaks. For methods using adsorbent traps, it is very important to determine the trap efficiency. Using APIMS to provide real time measurement of individual hydrocarbons is possible, in principle, but calibration is difficult, because larger hydrocarbons are collisionally dissociated in the ionization process.
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Yield Enhancement 49
A compromise approach that has gained some acceptance is to use TD GC/MS and sum all peaks corresponding to C6 and higher. The instrument is usually calibrated with a multi-component standard and results are reported "hexadecane". While the quantization provided by this method is approximate, and some species may be overlooked, it does at least emphasize the heavier hydrocarbons while providing a straightforward calibration.
Historically, applications for both O2 and H2 generally tolerate higher levels of N2 contamination than other contaminants, however, H2 as a carrier for Epitaxy now requires more stringent N2 levels and the table reflects this observation. Requirements for critical clean dry air (CDA), lithography purge gases, and supercritical CO2 supply are included. Whereas critical CDA may not always be conveniently or cheaply available, there is no technological barrier to its production. Analytical methods are usually the same as used for airborne molecular contamination in clean room air, such as bubbling through ultra pure water (for metals, sulfates, amines, etc.) or trapping on an adsorbent trap for organics. In each case, the sampler concentrates impurities so that requisite sensitivities are achieved when the sample is introduced to the analyzer (ICP-MS or ion chromatography for aqueous samples, GC-MS for desorption of organics). Such methods are time consuming by nature, and direct methods would be preferred if available. However, there is no apparent pressing need for real-time analysis. For SO2 there are convenient on line methods, e.g., UV fluorescence.
For specialty gases, contaminant values in etchants, dopants, and deposition gases have been expanded in Table YE3 to reflect the increase number of different materials in use, and to better delineate the processes they are used for. Particulate contamination is omitted, since online monitoring of particle concentrations is not commonly practiced and the efficacy of POU particle filters is well established. Whereas there is evidence that the most demanding applications, such as low temperature epi and its cleaning gases, will continue to benefit from improvements in purity as deposition temperatures are lowered, this is expected to be reflected in wider use of the best available purity rather than substantial improvements of those levels.
Tighter control over the variation in purity in both bulk and specialty gases is more important than improvement in absolute purity levels. However, the often more chemically reactive specialty gases present a more formidable challenge for maintaining of POS purity levels throughout the delivery to the point of process. Selected specialty gases, e.g., HCl are now commonly under statistical process control at the POS.
Novel materials--More detailed consideration of the impurity levels found in the growing number of novel materials used in processing will be increasingly important. Requisite purity levels for critical materials such as novel metal oxides, CMP slurries, low/high k dielectric materials, precursor materials (such as CVD and electroplating solutions) for barrier and conductor metals (such as Cu, Ta) have not been widely studied, and many of these materials have not been called out in Table YE3. An early attempt to start to catalogue and characterize the properties of the thin film precursors utilized in semiconductor processing is found in the supplementary material for this chapter.
Deposition precursors for thin film materials are often sensitive to moisture, air and high temperatures. Control over the delivery process from the POS to the reaction chamber is critical to high yielding performance. The use of very high purity carrier and purge gases in these systems are often required to prevent decomposition that can contribute detrimental molecular and particulate impurities. Traditionally bulk purifiers were used in the bulk gas delivery systems to remove particles and other homogeneous chemical contaminations like oxygen, or moisture present in the supply gases. However, with the development and commercial availability of point-of-use (POU) purifiers, there is a strong interest from end users to utilize point-of-use (POU) purifiers particularly for specialty gases needed for critical process steps with very critical level of contamination control. These point-of-use purifiers (POU) are highly effective to remove chemical contaminants to extreme low level (~ ppt), easy to use, easy to replace, with low cost-of-ownership. The capability of placing those point-of-use (POU) purifiers very close to inlet of process chamber, assures least travel path (less contamination) for process gases after chemical purification and filtration.
Novel measurement techniques and impact studies are needed to ensure that these materials are produced with the impurity specifications that meet technology requirements. Additional detail on the variety of thin film
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50 Yield Enhancement
precursors under consideration can be found in Liquid Chemicals section of Table YE3 and the supplementary precursor table.
2.2. CHARACTERIZATION, INSPECTION AND ANALYSIS
In 2011 the subchapter was defined to be extended to characterization, inspection and analysis. During the previous years the sub chapter was limited to inspection capabilities. This is facing the demands of nowadays yield enhancement in a broad application as e.g. `More than Moore' technologies but also power electronics and mechatronics and MEMS applications. Furthermore, the characterization, inspection and analysis demands of e.g. packaging and assembly could be taken into account.
2.2.1. ELECTRICAL CHARACTERIZATION METHODS AND VIRTUAL METROLOGY FOR YIELD CONTROL
In order to overcome the problems of missing sensitivity and high effort consuming metrology for yield control one focus of the YE group will be the partial replacement of physical based metrology to electrical diagnosis and virtual metrology wherever feasible. The use of all available data sources and approaches for data analysis will be further elaborated for yield monitoring. Hereby, a better balance of defect/contamination detection and fault diagnostics/control of electrical characteristics should be established by including statistical and systematic approaches into YE activities.
Furthermore, virtual metrology becomes more and more essential for yield considerations. Virtual metrology is the defined as the prediction of post process metrology variables (either measurable or non-measurable) using process and wafer state information that could include upstream metrology and/or sensor data. Refer to Yield Enhancement Chapter for more information.
2.2.2. WAFER DEFECT METROLOGY Defect metrology continues to be important towards smaller nodes specially considering new yield challenges like multiple patterning. The main way to detect yield impacting defects in the production is defect inspection. Therefore the most important requirements for inspection and review are now incorporated in the More Moore chapter. For Heterogenous Integration not small dimensions but 3D integration is the challenge. To find the right solutions for those inspection requirements and challenges will be the focus.
2.2.3. YIELD MANAGEMENT FOR PACKAGING AND ASSEMBLY
As technology requirements in the assembly and packaging area increases, yield loss and therefore yield improvement methodologies become essential. In this situation a clear benefit can be drawn from the experience in the FE. Yet the most appropriate methodologies have to be selected and FE yield tools need to be adapted to BE requirements. The task will be to define a dedicated roadmap.
Due to the changed focus of Yield Enhancement several cross TWG activities are envisaged, connections with More Moore (MM), Heterogeneous Integration (HI) and Heterogeneous Components (HC) are necessary.
3. POTENTIAL SOLUTIONS
3.1. WAFER ENVIRONMENTAL CONTAMINATION CONTROL
Process Equipment--Defect reduction in process equipment remains paramount to achieving defect density goals. Solutions and technology developments are expected to provide major enhancement capabilities in the next 15 years and continue to enable cost-effective high volume manufacturing for device dimensions below 90 nm. Refer to Figures YE3 and YE4. Equipment defect targets are primarily based on horizontal scaling. Vertical faults, particularly as they apply to the gate stack, metallic, and other non-visual contaminants, and parametric sensitivities need to be understood. New cleaning chemistries, in situ chamber monitoring, materials development, and other techniques including improved techniques of parts cleaning can help maintain chamber cleanliness run-to-run and dramatically reduce the frequency of chamber wet cleans. These
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Yield Enhancement 51
developments will also act to increase equipment utilization. Reduced backside wafer contamination control must drive both measurement technology and fundamental changes in equipment. Metal/particle cross contamination from backside to next wafer front-side, hot spots/depth of focus in lithography, and punch through on electrostatic chucks are all examples of issues that must be addressed in future tools. Particle avoidance techniques (o-ring material selection, gas flow/temperature management, wafer chuck optimization) will continue to play a key role in meeting defect densities. It is believed that a more fundamental understanding of reactor contamination formation, transport, and deposition will be required to enhance current equipment and process design and aid in the placement and interpretation of data from in situ sensors. These fundamental physical, chemical, and plasma reactor contamination models must be employed. In situ process control will become increasingly important to reduce process-induced defects and to minimize requirements for post-measurements. Intelligent process control at a tool requires a fundamental understanding of how parameters impact device performance. Open tool control systems that allow both users and equipment suppliers to easily integrate new sensor and new control software will be necessary to enable intelligent process control.
Process critical materials--Figure YE4 illustrates the set of potential solutions for prevention and elimination of defects. Further studies into device impact are necessary to validate any need for increased purities. System concerns such as corrosion potential may lead process concerns in seeking higher purities.
In order to accelerate yield enhancement for processes that incorporate new materials, it is very desirable that development studies include purity data as much as is practical. Studies of new materials (e.g., for gate dielectrics) are initially concerned with basic process performance, and later with integration issues. During those stages of development contamination is a relatively minor concern. However, if no information is collected, later yield enhancement efforts proceed with inadequate technical basis. Collecting and reporting both environmental and material contamination data whenever practical will lead to long-term benefits.
UPW--UPW systems meeting specifications do not appear to be large defect drivers for current device geometries. Based on this the Roadmap does not predict that significant changes are required for future geometries. As a Roadmap priority, specific defect mechanisms related to UPW are required to drive significant changes. The current focus is to understand the impact of the tool upon water quality, specifically particles, bacteria, and dissolved gasses, as well as to identify species that are suspected to be in UPW but are below the detection limit of available measurement methods. Improved measurement methodologies are required for organics, and organic ions to specify low-level contaminants in UPW. Recycling and reclaiming initiatives must drive improvements in rapid online analytical technology, especially detection of organics, to ensure that POU-recycled UPW is equal or better than single-pass water.
Chemicals--Figure YE4 also shows various technological areas that may be required to enhance and measure the purity of delivered chemicals to the wafer manufacturing process. Technology areas:
Wafer environment control--As the list of ambient contaminants to be controlled broadens so must measurement capabilities. Affordable, accurate, repeatable, real time sensors for non-particulate contamination are becoming increasingly necessary. The use of inert environments to transport and store wafers is expected to increase with process sensitivities. Pre-gate and pre-contact clean and salicidation are cited as processes to first require this capability. In addition, using inert environments offers the opportunity to reduce the introduction of moisture into vacuum load-lock tools, thereby decreasing contamination and load-lock pumpdown times. While closed carrier purging systems exist and are evolving, tool environments that may need to become inert, such as wet sink end-stations, present a challenge. As wafer isolation technologies evolve, design and material selection of carriers and enclosures will be critical for performance in isolating the wafers from the ambient and in not contributing contaminants themselves. In addition, the materials and designs must not promote cross-contamination between processes. Seal technology, low outgassing, and non-absorbing materials development are key to effective wafer isolation deployment.
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52 Yield Enhancement
First Year of IC Production DRAM 1/2 Pitch
New FOUP Outgassing / Contamination
SUBSTRATE
WAFER
RETICLE
Off line AMC measurement in laboratory
X
0
Inline AMC measurement inside FOUP in fab
X
0
Inline AMC measurement inside 450mm FOUP
and MAC in fab
X
0
Used FOUP Outgassing / Contamination (no wafer inside)
Off line AMC measurement in laboratory
X
0
Inline AMC measurement inside FOUP in fab
X
0
Inline AMC measurement inside 450mm FOUP
and MAC in fab
X
0
Vacuum purge and heating
X
0
Wafer Cross Contamination Inside FOUP (e.g acids after dry etch, oxygen or humidity before EPI clean)
Inline AMC measurement inside FOUP in fab
X
0
Integrated AMC measurement inside load port
X
0
Vacuum purge : outgass the FOUP with wafers
under vacuum and fill it with N2
X
0
N2 purge station : injection of N2 inside FOUP
with wafer
X
0
N2 purge station integrated in stocker : injection
of N2 inside FOUP with wafers
X
0
FOUP change : wafer transfer in a clean FOUP
during q-time
X
0
Purgeable load port : injection of N2 when the
FOUP is connected to the EFEM
X
0
Outgassing chamber integrated in process
equipement
X
0
Wafer tranfer under vacuum
X
0
SUBSTRATE LOCATION
STORAGE
PROCESS TRANSPORT
2013 32nm
X
0
0
X
X
X
X
X
X
X
0
0
X
X
X
X
X
X
X
0
0
X
X
X
0
X
0
X
0
X
X
0
X
X
0
0
X
0
X
0
X
0
0
X
0
0
X
X
2014 28nm
2015 25nm
2016 22nm
2017 20nm
2018 18nm
2019 16nm
This legend indicates the time during which research, development, and qualification/pre-production should b e taking place for the solution.
Research Required Development Underway Qualification / Pre-Production Continuous Improvement
Figure YE3
Wafer Environment and Reticle Environment Contamination Measurement and Control Potential Solutions (last updated in 2013)
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Yield Enhancement 53
Wafer Environment Contamination Control Potential Solutions- UPW
First Year of IC Production
2015 2016 2018 2020 2022 2024 2026 2028
DRAM 1/2 pitch, nm (contacted)
24
22
18
15
13
11
9.2
7.7
GENERAL
Fluid purity impact on device yield / performance
Contaminant based process control
Ultra Pure Water Particle online metrology 10 nm [A] Particle online metrology 5 nm [A]
Effective Filtration at 10nm particle size [A]
Effective Filtration at 5nm particle size [A]
Improved components to reduce particle generation (IXresin, coated pumps, etc.) [C]
Off-line test for particle filtration performance validation [A]
Correlation of specifc organic functional groups to wafer defects via Failure Mode and Effect Analysis [D]
Correlation of specifc organic functional groups to wafer defects via Failure Mode and Effect Analysis [D]
On-line detection of the critical organics (non-volatile) needs development [D]
Need to develop organic deposition model (sticking, removable, etc.) [D]
Use on-line TOC as way to control total organics (assuming that all is critical) [D]
Need to define effect of UPWborne H2O2 to manufacturing process
Drivers: [A] killer particle control [B] critical particle effect [C] critical particles and organics [D] critical organics
Thislegend indicatesthe time during which research, development, and qualification/pre-production should be taking place for the solution. Research Required
Development Underway Qualification/Pre-Production
Continuous Improvement
Figure YE4 Wafer Environmental Contamination Control Potential Solutions-UPW
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54 Yield Enhancement
Wafer Environment Contamination Control Potential Solutions - Liquid Chemicals
First Year of IC Production
2015
DRAM 1/2 pitch, nm (contacted)
24
GENERAL
Fluid purity impact on device yield / performance
Contaminant based process control
CHEMICALS - Metrology Development of 40 nm particle counter [A] Development of 20 nm particle counter [A] Development of 10 nm particle counter [A] Particle characterization to identify source of contamination [A], (for components and systems) Bubble discrimination of reactive chemistries [A] Improved metrology for concentration measurements[B] Surfactant concentration measurement and control [B] Anion & cation measurement in process chemicals, e.g. cleaning chemicals [A] Organic measurement (TOC and speciation) in process chemicals, e.g. H2O2, IPA [A] Contaminant characterization in CMP slurries, e.g. zeta potential, large particle size [A]* Contaminant characterization in CMP slurries, e.g. H2O2 concentration [B] Characterization of CMP slurries, e.g. Particle size distribution [B] On-line contaminant and constituent measurement in plating chemicals, e.g. copper sulfate, organic additives [A],[B] Improved blend accuracy taking into account incoming chemical concentration changes (closed loop control capability) [B] Closed loop point of use blending improvements [B]
CHEMICALS - Com ponents and System s Filtration 0.02/0.04 m w ith high flux (1 gpm/0.5 psi/10"/1cP) [A] Filtration sub 0.02 m w ith high flux (1 gpm/0.5 psi/10"/1cP) [A] Filtration sub 0.01 m w ith high flux (1 gpm/0.5 psi/10"/1cP) [A] Ionic POU purifiers (<1 ppt metals) [A] Inline End point detection for Ionic POU purifiers [A] Improved components to reduce particle generation, e.g. tubing, valves, pumps, fittings, etc. [A]
Improved system startup & f lushing methodology to more quickly reach particle target and reduce chemical usage [A]
Improved flow capacity and increased pressure for pumps [C]
Improved flow capacity increased pressure and temperature for piping components [C] Reduced pressure f luctuations by improved BCD system perf ormance and by better pressure and flow control [A], [B]
Improved connection technology (reduce leakages and increase reliabilitiy) [A], [D]
Decrease permeation of piping components (eg HCl permeation) [A], [D]
Higher purity resins and components (metals, organics, anions, cations, surface smoothness, permeability) [A] Elimination of particle sources in chemical distribution system including POU (particle prevention in chemical conditions) [A], (for EUV mask cleaning)
2016 22
2018 18
2020 15
2022 13
2024 11
2026 9.2
2028 7.7
*Slurries are also looked at in terms of changes in active components (e.g., H2O2)
Driver: [A] Purity [A] Purity - components and systems [B] Process control [C] Capacity [D] Maintenance
Thi s l egend i ndi cates the ti me duri ng whi ch research, devel opment, and qual i fi cati on/pre-producti on shoul d be taki ng pl ace for the sol uti on.
Figure YE5
Research Required Development Underway Qualification/Pre-Production Continuous Improvement
Wafer Environmental Contamination Control Potential Solutions-Liquid Chemicals
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Yield Enhancement 55
3.2. CHARACTERIZATION, INSPECTION AND ANALYSIS
For pattern wafer inspection the requirements the next years will be to overcome issues of detection of the defects within the nuisance signal. This is correlated to the issue to obtain high sensitivity at high throughput. . 3 d inspection capability will become very important for More than Moore technologies. The introduction of multi layer patterning will increase the importance of wafer inspection in lithography.
New solutions and roadmap for characterization and inspection in the packaging and assembly will be incorporated.
First Year of IC Production
Pattern Wafer Inspection High sensitivity at high throughput High signal to noise ratio
2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024
High Aspect Ratio Inspection High sensitivity at high throughput High signal to noise ratio
Detection of volatile and
non-volatile organic
surface contamination laboratory scale quantification and qualification development of in line method in line monitoring
Thi s l egend i ndi cates the ti me duri ng whi ch research, devel opment, and qual i fi cati on/pre-production should be taking place for the solution. Research Required Development Underway Qualification / Pre-Production Continuous Improvement
Figure YE6 Characterization, Inspection and Analysis Potential Solutions (last updated in 2011)
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56 Yield Enhancement
4. YIELD ENHANCEMENT SUPPLEMENTAL LINKS
Industry Goals for Particle Measurements In Liquid Chemicals (updated June 2015) - Set LPC goals for the future Feb2015 Liquid Chems.doc
Ion Table - ITRS-UPW+Chem Ion FMEA 07-28-2015.xlsx Mixing Calculation - ITRS_MixingCalc_HPM_100207.xls Advanced Analytical Methods for Particle Control in the Wafer Environment - Particles Libman SPCC rev2.pdf SEMI 5621A new standard (draft) "Guide for determining the quality of ion exchange resin used in polish
applications of Ultrapure Water System" - 6521A Draft for Ballot Cycle 8 11092014.pdf: Organic Speciation Benchmark Study Summary April 2013.pdf AMC monitoring programs - AMC_MonitoringProgram_090730_NBR.xls AMC definitions - AMC_ITRS_Definitions_090724_AN.xls Bulk and Specialty Gases - ITRS_SG_ContList_070913_NBR.xls Precursor Table - 1403-14 rev 2 master precursor table 2013.doc Precursors in production - 1403-14 precursors in prodn 2013.doc
5. REFERENCES
[1] Semi, Standard Practices for the development of Ship To Control Process Limits. 2008. [2] Funke, H. H.; Grissom, B. L.; McGrew, C. E.; Raynor, M. W., Techniques for the measurement of trace moisture in high-purity electronic specialty gases. Review of scientific instruments 2003, 74 (9), 3909-3933. [3] Alvarez Jr, D.; Spiegelman, J.; Heinlein, E.; Ramos, C.; Holmes, R. J.; Shamsi, Z., New Chemical Vapor Delivery Systems for Surface Cleaning. Solid State Phenomena 2013, 195, 25-29. [4] Norton, E. T.; Amato-Wierda, C., Kinetic and Mechanistic Studies of the Thermal Decomposition of Ti (N (CH3) 2) 4 during Chemical Vapor Deposition by in Situ Molecular Beam Mass Spectrometry. Chemistry of materials 2001, 13 (12), 4655-4660.
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