CVD-Process-Introduction教學(xué)講解課件

DCVDProcessIntroductionWhat’sDCVD?CVDcomponentCVDProcessapplicationCVDfilmindexComponentsofCVDsystemsWhat’sDCVD?DCVDmechanismDCVDprocessapplicationDCVDfilmcharacteristic&indexSACVDPECVDHDPCVD

DCVDProcessIntroductionWhat’sDCVD?DCVD

Theprocessofdepositingsolidfilmsusingvapororgasesasthesourcematerial.Thesesolidfilmsareusedforinsulationbetweensemiconductorlayers.DielectricAmaterialthatconductsnocurrentwhenavoltageisappliedtoacrossit.OxideandNitridesaredielectricmaterials.Chemical

Thereisachemicalreactionatthewafersurfaceasfilmisdeposited.Vapor

Thereactantareeithergasesorvapor.DepositionAsolidfilmisdepositedonthesurfaceofthewaferasaproductofthereactionbetweensourcegasesComponentsofCVDsystemCVDprocessdescriptionA).Gas/VaporphaseprecursorsintothereactorB).PrecursorsdiffuseacrosstheboundarylayerC).PrecursorsadsorbonthesubstrateD).AbsorbedprecursorsmigrateonthesubstrateE).ChemicalreactiononthesubstrateF).ByproductdesorptionsG).ByproductdiffuseacrosstheboundarylayerH).Byproductoutofreactor(A)(B)(C)(D,E)(F)(G)(H)BoundarylayerDCVDProcessSilaneprocess:

Oxide:SiH4+N2O plasma&heat

SiOx+N2+H2+H2O+othervolatilesSiH4+O2SiOx+H2+H2O+othervolatilesNitride:SiH4+N2+NH3

plasma&heat SiNxHy+othervolatilesSION

SiH4+N2O plasma&heat

SiOx

Ny+N2+H2+H2O+othervolatilesSilaneprocesschambercleanNF3+SiO2plasma&heatSiF4+N2+othervolatilesNF3+SiNplasma&heatSiF4+N2+othervolatilesplasma&heatDCVDProcessOzoneTEOSProcess:USGO3 heat O2+OO+Si(OC2H5)4

plasma&heatUSG+volatileorganicsPSGO+TEOS+TEPOheatPSG+volaticorganicsBPSGO+TEOS+TEPO+TEBplasma&heatBPSG+volatileorganicsTEOSchambercleanC2F6+NF3+SiO2

plasmaSiF4+CO+N2+othervolatileSurfaceAdsorption

SubstratesurfaceChemisorbedprecursorPhysisorbedprecursorBondingEnergySurfacedistanceChemisoptionStrongbondingenergyprecursor&surfaceVerylowsurfacemobility&badstepcoverageSiH4gasPhysisoptionWeakbondingenergyprecursor&surfaceHighsurfacemobility&goodstepcoverageTEOSgasDCVDApplicationin18LGShallowTrenchIsolation(STI)Anti-reflectedCoating(DARC)PremetalDielectric(ILD)IntermetalDielectric(IMD)PassivationDielectric(PASS)1.5k?SRO+6kASINMet1Met2Met3Met4Met5Met6Gox38?(El.)0.15m0.15m0.35mPoly2k?SiON400?ILD7.5k?COSiIMD19.0k?IMD29.0k?IMD39.0k?IMD49.0k?IMD510.5k?HDP10.0k?SiN+SRO7.5k?8.7k?4.8kA4.8k?4.8k?4.8k?4.8k?10k?HDPDielectricfilmcharacteristics

RefractiveIndex(R.I.)SpeedoflightinavacuumSpeedoflightinthefilmR.I.=Surfaceinterfaceθ2

θ1Vacuumn1Filmn2

n1sinθ1=n2sinθ2SiO2=1.46,Si3N4=2.01,Air~1(Referenceλ=633nm)R.I.SOG

SiO2SROSiONUVSiNSiNDARCPoly

1.381.461.501.751.92.02.0~2.53.8~4.0Oxygen/NitrogenrichSiliconrichDielectricfilmcharacteristics

PECVDrefractiveindextrendDielectricfilmcharacteristics

Depositedfilmthickness

Depositionrate=Depositedtime

Thicknessbeforewetetch-Thicknessafterwetetch

Wetetchrate=Wetetchtime

ThicknesschangeoftheCVDfilm

Wetetchrateratio=(WERR)Thicknesschangeofthethermaloxidefilm(A/min)Dielectricfilmcharacteristics

ThicknesschangeafterthermalcycleShrinkage=Standarddeviation(σ)(Non-)Uniformity=Meanvalue(

)Σ(XI-)2

σ=N-1Thicknessbeforethermalcycle

╳100%i=1~nX1+X1+…….+XNNDielectricfilmcharacteristics

StressBarewaferCompressivestress(-)Tensilestress(+)Afterdeposition△L=α

△TL

α

Coefficientsofthermalexpansion(in10-6C-1)

SiO2=0.5 Si=2.5Si3N4=2.8 W=4.5Al=23.2Dielectricfilmcharacteristics

StresscalculatedE

Stress=(-)1-vh2

6t1

Rafter1

RbeforeSubstrateYoung’smodulusSubstratethicknessSubstratepossion’sratioFilmthicknessWafercurvatureradius*1Mpa=106Pa=107dynes/cm2WhyUsingSABPTEOS?

Sub-atmosphericdopeTEB/TEPOwithTEOS/O3Goodgap-fillingcapabilityandPlanilization

forILDLayerTrapNa+LowerReflowTemperatureNonePatternSensitivityThroughputSACVD(Sub-AtmosphericCVD)HardwareintroductionINTERLAYERDIELECTRIC(ILDScheme)PE-SION400ADEPSABP-TEOSDepositionBPSGFLOW PETEOSdepositionOxCMPforILDN-WellP-WellP+P+N+N+2K?SABPSG10.5K?PETEOS400?SINOPECVD

SiH4+N2OplasmaSiOx(Hy)+othervolatiles(400C)SiH4+N2+NH3plasmaSiNx(Hy)+othervolatiles(400C)SiH4+N2O+NH3+N2

plasmaSiOxNy(Hz)+othervolatiles(400C)SiH4+N2O+He

plasmaSiOxNy(Hz)+othervolatiles(400C)WhyneedPECVD?LowtemperatureformetallizationprocessHighdepositionrateforWPHR.I.Adjustable(DARC,SRO)PECVD(PlasmaenhancedCVD)

PECVD(PlasmaenhancedCVD)

ACDielectricARC

DARC:DielectricAnti-ReflectiveCoating

Eliminatetheunwantedreflectionsbyphaseshiftcancellation

ofunwantedwavelengthPECVDOxynitride(SiH4+N2O+He→SiON)PECVDApplication(0.18Logic)

1.5k?SRO+6kASINMet1Met2Met3Met4Met5Met6Gox38?(El.)0.15m0.15m0.35mPoly2k?COSi4HDP10.0k?SiN+SRO7.5k?6.8k?5.1k?5.1k?5.1k?5.1k?5.1k?10k?HDP

PESiONEtchstoplayerN-WellP-WellP+P+N+N+2k?SABPSG10.5k?PETEOS

ILDPETEOS10.5KMet1N-WellP-WellP+P+N+N+6.5k?HDP11KAPEFSG

IMDPEFSG11KPass.PESRO1.5K/PESIN6KPolyDARCMetalDARCContact/ViaDARCWhyUsingHDP?

WhatistheHDP-CVD?=>HighDensityPlasma(HDP)isatypeofadvancedchemicalvapordeposition(CVD)technologyinwhichthedensityoftheinconventionalplasma-enhanced(PE)CVDtechnology.plasma(~1011-1012n/cm3)ishigherthanthatused

WhyweneedHDP-CVD?

=>HDP-CVDisconsideredaleadingtechnologyforthemostadvancedgap-fillingrequirementsin<0.35μmdesignrules.HDPCVD(HighDensityPlasmaCVD)

StepcoveragebacSidewallstepcoverage=b/aBottomwallstepcoverage=c/aAspectratio=h/sl:line,s:space

ArrivingangleStepcoveragetopressure&surfacemobilityrelativeoverhanghlsGapfill

TrapperprofileOverhangprofileNormalprofileVoidCM81SABPSGvoidissueHDP-CVDConcept

Silaneoxidedepositingandargonionetchingbackatthesametime.Whendepositionandsputterrateareproperlyadjusted,theHDPchamberandprocessiscapableoffillingnarrowgapsfromthebottomupwithoxideofhighqualityandspatialuniformity.Gap-fillingcapabilitydependentonratioofdepositiontosputteringD/S=(netdepositionrate+blanketsputteringrate)/

(blanketsputteringrate)Deposition=>DryEtching=>Deposition=>ContinuousProcessHDP-CVDConcept

HDP-CVDConcept

IMDHDPgap-fillvsD/SHDP-CVDConcept

HDP-CVDConcept

HDP-CVDConcept

Howtocontrolwafertemperatureduringprocess?ESC(ElectrostaticChuck)

1)Largeionbombardmentcomponentgeneratesmuchheatonwafer.2)BacksideHecoolingi