Critical Considerations for Metrology and Inspection in Solar Manufacturing Jeff Donnelly, Group VP - Growth & Emerging Markets July 2011
Outline
Process Control in Manufacturing Solar PV Trends Benefits of Automated Process Control Summary
2
How Do We “Really” Get Defects Down?
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Process Control: Across Multiple Industries Fertilizer Optimization for Corn Yield
“Zero Defect” in Automotive Chip Manufacturing
Parts
Engine ECU
Car
(1200 parts) ・・ ・・ ・・
Even if 1 ppm part defect
1200ppm Engine ECU defect
120 cars defective out of 100,000 car
Z.D. ( Zero Defect ) is needed
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KLA-Tencor Global leader in yield acceleration since 1976 Installed base ~21,000 tools > 5,300 employees ~ 3,400 technical personnel in 17 countries #1 Market Share in Process Control for 35 years >$1.5B R&D investments over last 4 years FY 2010 revenue: >$1.8B, ~>$3B for FY’11
KLA-Tencor Markets
Wafer 5
IC Fab
Reticle
Solar
LED
Service/Apps
PV Capacity Forecast GW
Overall CAGR expected to be 24% from 2010 -2015 Asia to dominate capacity By 2015, Asia will account more than 75 % of total capacity, with China having the largest installed capacity
Source: Goldman Sachs 6
Multiple Competing Technologies c-Si to maintain dominance. 100%
6% 1% 6%
90%
6%
80%
6% 1% 8% 7%
8% 2%
9% 2%
12%
10%
7%
6%
9%
9%
8%
4%
5%
7%
13%
13%
4%
5%
11% 4%
70% 60% 50% 81%
40%
77%
71%
74%
73%
69%
67%
2009
2010E
2011E
2012E
2013E
30% 20% 10% 0% 2007 Source: GTM Research
7
2008 Crystalline Si
Super Mono c-Si
CdTe
CIGS
a-Si
Goal is to Achieve Grid Parity
Average retail power price ($/kWh)
GRID PARITY
2010E
2014E
Average insolation (Kwh^2/day) Source: Goldman Sachs
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3 Levers to Improve Cost/Watt Efficiency Thickness Kerf loss
High volume production Reduce unit costs 22% price decrease when doubling module production volume
Scaling 21%
Productivity 25% Yield increase Manufacturing excellence Standardization 1% yield increase
~5% cost reduction cell manufacturing Source : Q.Cells 9
1% efficiency increase ~15% cost reduction cell manufacturing
Technology 54%
20µ thinner wafer ~7% cost reduction cell manufacturing
Process Control in a Solar Cell Fab Enables All 3 Levers BARE WAFER TEST Optical µ-cracks TTV & Rs Lifetime Surface roughness
LIFETIME TEXTURE INSPECTION Inline µ-PCD lifetime Off-line reflectivity measurement SHEET RESISTANCE Weighing for etch check Inline sheet resistance
Chemical etching & texturization
Classification
ELECTRICAL TEST In-line characterization of cell efficiency & class analysis Shunt inspection
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POCl3 diffusion
Co-Firing
µ-crack on Finished Cell camera, ultrasonic, stability CELL CLASSIFICATION (FS & BS) Inline camera systems
EDGE ISOLATION TEST Offline edge isolation test
P-glass removal
Backside printing
ARC-CONTROL Inline camera system
Silicon nitride ARC
Frontside printing
PRINT-INSPECTION (FS & BS) Inline camera systems Weighing to check added metal weight
Process Control Improves Learning Curve and Enables Capacity Potential Post-Coating Inspection: AOI Allows Faster Learning & Capacity Ramp
Small Reduction in output can lead to substantial $ loss
Cell Position y
LINE 1
Cell Position y
LINE 2
Cell Position x
Data Collection & Aggregation makes Fast Root-Cause Analysis Possible.
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Assumptions: ASP = $4/cell, 1200 UPH/30MW
Process Control Improves Learning Curve and Enables Capacity Potential Statistically Understand Yield Issues to Learn Fast & Ramp Fast
Small Reduction in output can lead to substantial $ loss
 In high volume production understanding cause of systematic defects is critical 
An integrated hardware and software solution enables quick understanding of root cause of systematic defects Assumptions: ASP = $4/cell, 1200 UPH/30MW
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Process Control for Improved Cell Efficiency Parametric Monitoring to Understand Efficiency Improvement Opportunities Finger Width
Efficiency Improvement Adds Substantial Revenue
Screen Changed
Time
Efficiency
16%
Entitlement Ρ
0.3% Improvement
Time 13
Assumptions: Cell ASP = $1/watt, Nominal 17% -efficiency capacity operating at average 16% production efficiency.
Process Control can Accelerate Innovation Selective Emitter
Metal Double Printing
Metal Wrap-thru
Emitter Wrap-thru
Inter digitated Backside Contact
Hetero Junction
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Process Monitoring Enables Higher Yield color & coating thickness
saw mark chipping
Chemical etching & texturisation
Âľcrack
POCl3 diffusion
Classification
Co-Firing
Alu paste defect
Silicon nitride ARC
Backside printing
busbar defect blister
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P-glass removal
Frontside Printing
finger knot
finger interrupt
KLA-Tencor Solutions for Process Control in a Solar PV Fab P6 / P16+ Profiler
Step Height Standards
Chemical etching & texturisation PVI-6 Wafer Inspection Âľcrack Inspection
POCl3 diffusion
P-glass removal
Silicon nitride ARC
Step Height Standards
Classification
Solar Reference Cells & Cert. Services PVI-6 Front & Backside Classifier 16
Silicon Nitride Standards
Resistivity Standards
Co-Firing
Fab Vision
Backside printing
PVI-6 Front & Backside Print Inspection
Frontside printing Aluminum
Thickness Standards
Thin Film PV Inspection Post Deposition Inspection
Final Quality after back end
Flasher test
I-V curve tracer Structuring Layer deposition
Structuring Chemical step
Incoming Substrate Quality
Layer deposition
Solar module
Structuring
Back end processing I-V curve tracer
Layer deposition Incoming quality
Structuring P3 Deposition front / backside contact Structuring P2 (Chemical steps) Depostion layer Structuring P1 Deposition front / backside contact Cleaning Backside glass
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End of Line Electrical Test
Future Process Control Requirements for Further Price/Watt Decrease Central control of all metrology tools (recipe, calibration, reference sets, etc.)
Introduction of wafer & cell tracking Integrated quality system for real-time process control 18
Introduction of wafer & cell tracking High resolution inspection & metrology
Summary: Benefits From Process Control Improved Performance and Lower Costs
Improved Production Entitlement: Highest, Stable Yields Quickly Identify and Solve
Reduce cycle time Increase process tool productivity
Yield Excursions
Faster Ramp: Yield
Maximize production efficiency
Quickly Identify and Solve Key Yield Issues
Reduce material at risk Detect and fix process issues earlier Faster Development: Understand requirements, Resolve gaps, Optimize Strategy
Reduce field failures Improve traceability
Accelerate time-to-market
Months
KLA-Tencor contributes directly to lowering Cost/Watt and improving performance (yield) 19
Copyright Š 2012 KLA-Tencor Corporation
www.kla-tencor.com