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Advanced Process Control Techniques to Increasing AMOLED Display Fabrication Yields
Elvino da Silveira
Outline
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Introductions & Trends
Test Methods and Results
Device performance increases need metrology & compensation
Mobility driving needs for production enhancements
Simulate demanding die misplacement and innovative compensation solutions
Beyond aadvanced packaging… display process control!
Challenges
Future Solution
About RudolphSemiconductor Process Solutions
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INSPECTMacro Defects Silicon to Die
Dicing and Chipping DetectionInterconnect Metrology
3D/2D InspectionResidue Detection
IMAGELithography down to 2µm
Fan-out and Cu PillarWafer and Panel
MEASUREOn Product and In-dieMulti-layer Film StacksUBM, RDL, PR, PI, DielectricsStructure CD
ANALYZEProcess AnalysisProcess ControlTool-centric and Fabwide
Wafer Panel
SILICON SOLUTIONS TO ENHANCE THE SEMICONDUCTOR VALUE CHAIN TEST
CORECOMPETENCIES
Display TrendsIncreased Mobility & Function Driving New Technology Adoption
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Higher pixel per inch (PPI)
OLED & µLEDS Flexible Substrates
Source: IHS
Trends Mandate Changes in Display Production Methods
Adoption of AMOLED
Products driving more adoption
Next generation products
New Form Factors
Production SolutionSoftware CapabilityTechnology
Innovative Solutions Based on innovation
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DATA COLLECTION
LITHIGRAPHY
METROLOGY
MODELING
COMPENDATION
Leveraging Technology and Software
PROCESS OPTIMIZATION
Challenge
Over the last few years, placement error has become a significant
challenge to Fan Out Packaging, Flexible materials, µLED and
AMOLED FMM.
Rudolph’s diverse capabilities address the challenge with our multi-
discipline teams
Teams competencies: Software, Inspection, Lithography
This is our solution for AP
Advanced Packaging Roadmap
Yole Development study predicted significant cost reductions with panel level packaging.
Future of advanced packaging 300mm to Panels
Stepper Specifications
Wafer/Panel size 200mm, 300mm, 300+, Panels*
Optics 2X reduction
Working distance 17mm
Exposure Field Size 59.4mm x 59.4mm, 52mm x 66mm
NA 0.10
Resolution 2µm L/S (i-line), 3µm L/S (ghi)
Wavelengths ghi, gh, i
AOI – Specifications
Wafer/Panel size 200mm, 300mm, 300+, Panels*
Inspection resolution 0.7µm
Review resolution 0.35µm
Autofocus “on the fly”
Residue detection >20nm
Inspection CD resolution 2µm
Illumination BF, DF, patented Clearfind™
Technology
Die Placement Error and Solution
Using advanced metrology and custom algorithms, the stepper adapts to the die placement errors
Feed Forward
SoftwareCOMPUTES OPTIMIZED STEP MAP
Metrology SystemMEASURES DIE PLACEMENTAND ROTATION
RECONSTITUTEDPANEL OR WAFER
StepperEXECUTES OPTIMIZED STEP MAP
Additional processing induced error
Feed Forward
Pick and Place tool process and the mold compound process amplifies the placement errors
• Test Reticle Design
Experimental DOE
Overlay Structures
Test vehicle used predefined offsets for Layer 1 (Pad)
Predefined Die Offsets
Packages with Die Errors
Wafer Die Placement
Wafer Layout 7 x 7 array Stepper Metrology from S4D2
Stepper metrology confirms predefined offsets
AOI / Stepper Integration
AOI accuracy < +/- 2um
Modelled stage parameters
Mapping vector plot for nominal position die
Stepper Metrology from S1D1
StepFAST™ Algorithm Applied
Feed forward overlay results (left side)
StepFAST Algorithm Applied
Feed forward overlay results (right side)
• Similar to AP Display have diverse technologies and Materials
• Display processes• µLED placement
• FMM errors
• Materials:• Flex
• Larger substrates
• Warpage impact
• Results will be the subject of a future paper
Display Challenges
Compensation Method For Display
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• Vector plot of simulated FMM distortions
• Vector plot of simulated compensation results for AMOLED Production Process
SummaryComprehensive Solution
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Advancements in Mobility Products
Increased unit counts and AMOLED Adoption
Driving need for process optimizations
Integrated Solutions Address
Process optimizations requires metrology, data collection, modeling and automated
optimizations,
Solutions require collaboration…
New applications will be the subject of a future talks
Special thanks to Simax our China partner
About the Speaker
Vice president of business development at Rudolph
Technologies, with responsibilities to identify new
markets and develop strategies to prosecute the
opportunities. Until the Rudolph acquisition in
December 2012, he served as president and
operations manager of Azores since its inception in
March 1999. Prior to forming the company, he was
employed by MRS Technology, Inc., as the vice
president of operations and worldwide customer
support. da Silveira has also held engineering and
customer support roles at Hampshire Instruments
from 1991 to 1993 and GCA/General Signal from
1984 to 1991. Mr. da Silveira holds a B.S. in
Mechanical Engineering from Northeastern University.
ELVINO DA SILVEIRA
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