STATUS AND READINESS FOR LARGE FORMAT FAN-OUT PACKAGING SEMI PACKAGING TECH SEMINAR Vila do Conde, Portugal June 2015 Roger McCleary June 18, 2015
AGENDA Introduction Fan out Visibility Lithography Challenges Wafer vs Panel Productivity Benefits Total Lithography Solution Summary 2
RUDOLPH LITHOGRAPHY SYSTEMS GROUP Headquarters in Wilmington, Massachusetts More than 400 years of combined lithography experience dating from the 1980s with GCA and ASML steppers Large IP portfolio surrounding Advanced Packaging and Display Lithography Well developed supply chain poised for growth and technology advancement 3
THE CHALLENGE There is no long term visibility in the Semiconductor Back-End industry but we do expect fan-out to grow significantly!
Roadmap Gen 2-370x470 mm Gen 3-550 x 670 mm Gen 3.5-600 x720 mm 330mm 300mm Source: Yole 5
Status and Readiness: 300/330mm Wafers 450mm Wafers Panels from 470x370mm² to 720x600mm² All present same challenge Lithography Challenges - Minimum Resolution - Sidewall angle/cd Control - Depth of Focus - Exposure Field Size - Alignment and Overlay - Warped Wafers or Panels - Throughput (Impact on COO) - Yield 6
LITHOGRAPHY REQUIREMENTS Advanced Packaging diverse production methods Advanced Packaging High resolution lithography (down to 2um line/space) for redistribution layer (RDL) Imaging of Polymers with controlled slope (Passivation) Thick resist Imaging for: Dry etching of Vias (TSV) Electroplating (Cu Pillars) Extremely cost sensitive 7
INTRODUCTION: WHY FAN-OUT? Lower cost Thinner Technical advantages over: FC BGA WLCSP (Fan-In) Illustrations by Yole
FAN OUT EVOLUTION Desire to increase functionality by integrating multiple die into a single package These packages will drive die size, making them larger Higher I/O required, driving finer resolution As a result, the piece count is reduced on a wafer like substrate Therefore to maintain economics, a migration to larger substrates is required 9
INTRODUCTION: WHY PANEL FAN-OUT (P-FO)? Economy of Scale! Large panels = more devices Lower cost per device Substrate Generation Size in mm (Up To) Wafers Up to 330mm Generation 2 470 x 370 Generation 3 650 x 550 Generation 3.5 720 x 600
To achieve economy of scale, leverage FPD equipment infrastructure Large panels = more packages Substrate Generation Size in mm (Up To) Number of Die/substrate (8mm x 8mm) Number of Exposure Steps by JetStep Wafers Up to 330mm 992 24 Generation 2 470x370 2688 48 Generation 3 650x550 5040 90 Generation 3.5 720x600 6720 120 Achieving lower cost per package 11
LITHOGRAPHY APPLICATION SPACE 15µ AP WAFER ALIGNERS PCB LASER DIRECT WRITER Resolution 10 µ 5 µ AP WAFER LITHOGRAPHY JetStep W-Series Lithography System JetStep S-Series Panel Lithography System 2 µ 1 µ Future Roadmap Future Roadmap 150 mm 200 mm 300 mm Fan-out 450 mm Gen 2 Gen 3 Gen 3.5 Round Wafers Rectangular Panels Glass / Organic Trend is higher resolution and larger substrate size
LITHOGRAPHY CHALLENGES - 1 Typical Advanced Packaging Lithography requirements Advanced Packaging 2um line/space lithography for redistribution layer (RDL) Imaging of Polymer with controlled slope (Passivation) Thick resist lithography for dry etching of vias (TSV) Patterning of thick resist for Electroplating (Cu Pillars) Low cost
LITHOGRAPHY CHALLENGES - 2 Litho Challenge Min. resolution Overlay accuracy Sidewall angle & CD control Depth of Focus Exposure field size Handling of warped wafers or substrates Requirement 2µm Lines/Spaces 0.5µm (layer to layer) >80 / ±10% >15µm >35mm, (no stitching) >5mm
CHALLENGE: MINIMUM RESOLUTION: FULL FIELD 2UM RDL IMAGING +12 μm -12 μm 0 μm Field Size: 59.39 mm² DOF: 24μm Dose: 740mJ Thickness: 6 μm -12 μm AXIS -12 μm 0 μm +12 μm Top Left 0 μm Top Right -12 μm Bottom Left +12 μm Bottom Right -12 μm 0 μm 0 μm +12 μm +12 μm
CHALLENGE: EXPOSURE FIELD SIZE Fan-Out packages can be large Field stitching should be prevented (throughput & overlay challenge) Large field is a key requirement Field size: Anything within 84mm circle» 59.4mm x 59.4mm square» 53.8 x 64.5 mm» 51.96 x 66 mm Large Field Advantage: Throughput & No Stitching
CHALLENGE: WARPED SUBSTRATES Wafer & panel warpage is common for back-end applications: >2mm up to 6mm Driven by thick films and various materials (metal, mold compound, polymers, resists, etc.) CTE mismatching
LARGER SUBSTRATE CHALLENGES: Die placement (pick and place equipment for panels) Resist Uniformity Substrate Warpage Overlay: 2 different approaches: Full panel populated with dies Panel with subpanels Different alignment strategies: Full panel: 3 or 4 points EGA Sub panels: 2 EGA and 3 to 4 EGA per sub panels. Impact on T-put 18
CHALLENGE: DEPTH OF FOCUS (DOF) Depth Of Focus is a function of lens Numerical Aperture Large DoF critical for: Thick resist Topographic variations Residual warpage (after chucking) Front-End Steppers are not suitable for this application as they have high NA, small field size and require flat wafers High n.a. Stepper Depth of Focus Substrate Thick Resist JetStep Large Depth of Focus On The Fly Auto Focus
PRODUCTIVITY INCREASE: WAFERS TO PANELS 8x8mm² 4 layers per die 9 EGA 1X Stepper 300mm wafer JetStep (wafer) 300mm JetStep Panel 650x550mm² (Gen 3) Exposure wavelength/field size diameter ghi / 84mmØ ghi / 84mmØ Field size in mm² 68x28 52x66, 64.5x53.8 or 59.4x59.4 52x66, 64.5x53.8 or 59.4x59.4 Illumination power 2400mW/cm² 1500mW/cm² 1500mW/cm² Number of exposures per substrates 44 24 90 Dose = 600mj Estimated Throughput (die/h) 47,817 57,477 124,794 Productivity Increase X1 X1.20 X2.17 Dose = 1000mj Estimated Throughput (die/h) 42,504 51,971 107,113 Productivity Increase X1 X1.22 X2.06 >2x Productivity Achievable with Gen 3 Panels over 300 mm Wafer
PRODUCTIVITY IMPROVEMENT FOR PANELS OVER 300 MM WAFERS PRODUCTIVITY: PANELS TO 300 MM WAFER 2.50 Average dose from 100 to 2500mJ/cm² 2.00 1.50 1.00 0.50-470x370mm² panel 510x510mm² panel 650x550mm² panel 720x600mm² panel Productivity Improvement for Panels > 1.5x to 2.35x Over 300 mm Wafers 21
TOTAL PHOTOLITHOGRAPHY SOLUTION: ANALYZE DIE PLACEMENT, OVERLAY AND CD COMPENSATE DIE PLACEMENT, OVERLAY & CD WITH JOB PARAMETERS MONITOR CONTROL AND OPTIMIZE TOOL PARAMETERS MEASURE DIE PLACEMENT, OVERLAY AND CD IMPROVE YIELD Measure, Analyze, Compensate and Optimize Discover Lithography
READINESS FOR LARGE FORMAT FAN OUT TOTAL LITHOGRAPHY ADVANTAGES: Yield improvement: Overlay Process stability Discover Lithography Results Tightened to Target Results Centered to Target Results Tightened to Target Results Centered to Target 23
READINESS FOR LARGE FORMAT FAN OUT and Tracking: Automatic calibration Real time Autofocus at each exposure: Improve DOF on warped substrate Improve CD control Contamination (lens Purge) Outgassing (large working distance) Topography Dose accuracy with dose detector integrated in illuminator Illumination Uniformity Ambient Temperature, Pressure and humidity 30 mm 24
Throughput Improvement in % WPH Throughput improvement in % WPH TOTAL LITHOGRAPHY ADVANTAGE: Throughput advantage: Less Enhanced Global Alignment (EGA) points needed: 2 300mm wafer, 8410 ghi lens, Illumination intensity=1500mw/cm² Discover Lithography THROUGHPUT INCREASE WHILE REDUCING THE NUMBER OF EGA TO 2 WITH 21 EXPOSURES 100mJ/cm² 800mJ/cm² 1400mJ/cm² THROUGHPUT INCREASE WHILE REDUCING THE NUMBER OF EGA TO 2 WITH 43 EXPOSURES 100mJ/cm² 800mJ/cm² 1400mJ/cm² 21% 17% 14% 13% 9% 7% 6% 10% 8% 6% 4% 4% From 9 to 2 EGA Reducing the number of EGA From 5 to 2 EGA From 9 to 2 EGA Reducing the number of EGA From 5 to 2 EGA 25
SUMMARY & CONCLUSIONS Fan Out is growing faster than overall industry Enabling new approach for System Integration (SiP) Lithography is key part of manufacturing process 2x Stepper system is suitable lithography approach Scalable from 200/300mm to 450mm and panels Economy of scale benefits (lower cost, higher throughput) 120% Panel-based Interposer (and Fan-Out) 100% 80% ~27% Cost ~25% Cost Reduction 60% 40% Investigation Development Pre-Production High Volume Production 20% 0% Dose = 600mJ/cm2 Dose = 800mJ/cm2 2014 2015 2016 2017 JetStep Wafer Sysem JetStep Panel System
ACKNOWLEDGEMENTS Thanks to the following Rudolph Technologies Team Members - Philippe Cochet - Keith Best Thank You roger.mccleary@rudolphtech.com Rudolph Confidential