HD-4000 Profile Optimization Through Process Enhancement · 2021. 1. 12. · HD-4000 4000 Profile Optimization Through Process Enhancement Shannon Dunn 2004 Symposium on Polymers

HDHD--40004000 Profile Optimization Profile Optimization Through Process Through Process EnhancementEnhancement

Shannon DunnShannon Dunn

2004 Symposium on Polymers

5/04 S.Dunn5/04 S.Dunn

AbstractAbstractPolyimides have been frequently used as stress release layerPolyimides have been frequently used as stress release layer for wafer level packaging [WLP] especially with Cfor wafer level packaging [WLP] especially with C--4 bumped 4 bumped die. HDdie. HD--4000 is a high Tg photosensitive polyimide [PSPI] 4000 is a high Tg photosensitive polyimide [PSPI] developed to replace earlier nondeveloped to replace earlier non--photosensitive wetphotosensitive wet--etch etch polyimides thereby improving wafer throughput as well as polyimides thereby improving wafer throughput as well as resolution. Over the years a number of processing resolution. Over the years a number of processing enhancements have been developed to improve the wall slope enhancements have been developed to improve the wall slope of wetof wet--etch polyimide to achieve improved side wall coverage, etch polyimide to achieve improved side wall coverage, reduce stress and limit the pinch points in subsequent underreduce stress and limit the pinch points in subsequent under-- bump metal [UBM] layers. This presentation will focus on a bump metal [UBM] layers. This presentation will focus on a variety of process optimizations done in conjunction with HDvariety of process optimizations done in conjunction with HD-- 4000 to achieve similar smooth side4000 to achieve similar smooth side--wall profiles and their wall profiles and their resulting impact on sidewall slope of cured PSPI films.resulting impact on sidewall slope of cured PSPI films.


Standard HDStandard HD--4000 Process 4000 Process ProcessProcess UnitUnit ConditionCondition RemarkRemark EquipmentEquipment

CoatCoat rpmrpm 25002500 Thick.Thick.-- 11um11um SVG TrackSVG Track

SoftbakeSoftbake C/secC/sec 85/90 + 95/9085/90 + 95/90 Proximity HotplateProximity Hotplate SVG TrackSVG Track

ExposureExposure mJ/cm2mJ/cm2 115115 II--linelineUltratechUltratechStepperStepper

Post ExposurePost ExposureBakeBake C/secC/sec 80/6080/60 Proximity HotplateProximity Hotplate SVG TrackSVG Track

DevelopDevelop secsec 4545 Solvent SpraySolvent Spray SVG TrackSVG Track

CureCure C/minC/min 200/30 + 375/60200/30 + 375/60N2 Purge,N2 Purge,

Thickness Thickness -- 5um5um Koyo OvenKoyo Oven


Standard HDStandard HD--4000 Profile4000 Profile


Profiles with Focus Offset AdjustProfiles with Focus Offset Adjust


Post Develop Bake ProcessPost Develop Bake Process

ProcessProcess UnitUnit ConditionCondition RemarkRemark EquipmentEquipment


SoftbakeSoftbake C/secC/sec 85/90 + 95/9085/90 + 95/90ProximityProximityHotplateHotplate SVG TrackSVG Track

ExposureExposure mJ/cm2mJ/cm2 115115 II--linelineUltratech Ultratech StepperStepper


Post DevelopPost DevelopBake Bake C/secC/sec 150/100+200/100150/100+200/100

Proximity Proximity HotplateHotplate SVG TrackSVG Track




HDHD--40004000 Post Develop Bake ProfilePost Develop Bake Profile


Post Develop Bake with Focus AdjustPost Develop Bake with Focus Adjust


Post Exposure Queue Process Post Exposure Queue Process





Post ExposurePost ExposureQueueQueue minsmins 3030

Wait before Wait before DevelopDevelop N/AN/A



ThicknessThickness--5um 5um Koyo OvenKoyo Oven


HDHD--4000 Queue Profile4000 Queue Profile


Queue with Focus AdjustQueue with Focus Adjust


Post Exposure Queue with Post Post Exposure Queue with Post Develop Bake Process Develop Bake Process






Wait before Wait before DevelopDevelop N/AN/A





ThicknessThickness--5um 5um Koyo OvenKoyo Oven


HDHD--4000 Queue with Hardbake 4000 Queue with Hardbake ProfileProfile


Queue with Hardbake thru Focus Queue with Hardbake thru Focus AdjustAdjust


Broadband ProcessBroadband Process



SoftbakeSoftbake C/secC/sec 85/90 + 95/9085/90 + 95/90Proximity Proximity HotplateHotplate SVG TrackSVG Track

Exposure Exposure mJ/cm2mJ/cm2 100100 BroadbandBroadbandUltratechUltratechStepperStepper

Post ExposurePost ExposureBakeBake C/secC/sec 80/6080/60






Thickness 5umThickness 5um Koyo OvenKoyo Oven


HDHD--4000 Broadband Profile4000 Broadband Profile


Broadband Exposure with Queue Broadband Exposure with Queue ProcessProcess



SoftbakeSoftbake C/secC/sec 85/90 + 95/9085/90 + 95/90Proximity Proximity HotplateHotplate SVG TrackSVG Track

Exposure Exposure mJ/cm2mJ/cm2 100100 BroadbandBroadbandUltratechUltratechStepperStepper


Wait before Wait before Develop Develop N/AN/A







HDHD--40004000 Broadband with Queue ProfileBroadband with Queue Profile


HDHD--4000 Profile Optimization4000 Profile Optimization SummarySummary

Process modifications can be utilized to Process modifications can be utilized to achieve desired profile of HDachieve desired profile of HD--4000. Some 4000. Some of those process modifications are:of those process modifications are:

Focus Offset adjustmentFocus Offset adjustmentPost develop bake Post develop bake Post exposure queuePost exposure queueChange of exposure wavelength Change of exposure wavelength

It is also possible to combine several It is also possible to combine several process modifications to achieve the process modifications to achieve the required profile.required profile.


HDHD--4000 Processing Summary4000 Processing SummaryCondition Profile Pros Remarks

PEB with Focus Adjust Reduce Crown Stepper Needed

Queue with FocusAdjust

Reduce Crown/Increase Footing

Throughput Delay/Queue Time

Post Develop Bake (PDB) Eliminate Crown

Increased ProcessingTime

Queue withPost Dev Bake

No Crown Shallow Slope

Increase Processing/Decrease Throughput

BroadbandExposure

Reduce Crown/ChangeSlope Tool Dependent

BroadbandQueue/PDB

No Crown/ShallowSlope

Tool Dependent/Increased Processing/Queue Time

HD-4000 Profile Optimization Through Process EnhancementAbstractStandard HD-4000 Process Standard HD-4000 ProfileProfiles with Focus Offset AdjustPost Develop Bake ProcessHD-4000�Post Develop Bake ProfilePost Develop Bake with Focus AdjustPost Exposure Queue Process HD-4000 Queue ProfileQueue with Focus AdjustPost Exposure Queue with Post Develop Bake Process HD-4000 Queue with Hardbake ProfileQueue with Hardbake thru Focus AdjustBroadband ProcessHD-4000 Broadband ProfileBroadband Exposure with Queue ProcessHD-4000�Broadband with Queue ProfileHD-4000 Profile Optimization�SummaryHD-4000 Processing Summary

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HD-4000 Profile Optimization Through Process Enhancement · 2021. 1. 12. · HD-4000 4000 Profile Optimization Through Process Enhancement Shannon Dunn 2004 Symposium on Polymers