晶圆制造专题知识专业知识讲座课件

CrystalStructuresAmorphousNorepeatedstructureatallPolycrystallineSomerepeatedstructuresSinglecrystalOnerepeatedstructure2023/6/61AmorphousStructure2023/6/62PolycrystallineStructureGrainGrainBoundary2023/6/63SingleCrystalStructure2023/6/64WhySilicon?Abundant,cheapSilicondioxideisverystable,strongdielectric,anditiseasytogrowinthermalprocess.Largebandgap,wideoperationtemperaturerange.2023/6/65Source:http://www.shef.ac.uk/chemistry/web-elements/nofr-key/Si.html2023/6/66UnitCellofSingleCrystalSilicon2023/6/67CrystalOrientations:<100>xyz<100>plane2023/6/68CrystalOrientations:<111>xyz<100>plane<111>plane2023/6/69CrystalOrientations:<110>xyz<110>plane2023/6/610<100>OrientationPlaneAtomBasiclatticecell2023/6/611<111>OrientationPlaneSiliconatomBasiclatticecell2023/6/612IllustrationofthePointDefectsSiliconAtomImpurityonsubstitutionalsiteFrenkelDefectVacancy(空位)orSchottkyDefectImpurityinInterstitialSiteSiliconInterstitial間隙2023/6/613DislocationDefects2023/6/614FromSandtoWaferQuartzsand:silicondioxideSandtometallicgradesilicon(MGS)ReactMGSpowderwithHCltoformTCSPurifyTCSbyvaporizationandcondensationReactTCStoH2toformpolysilicon(EGS)MeltEGSandpullsinglecrystalingot2023/6/615FromSandtoWafer(cont.)Cutend,polishside,andmakenotchorflatSawingotintowafersEdgerounding,lap,wetetch,andCMPLaserscribeEpitaxydeposition2023/6/616晶圓形成之步驟

FromSandtoSilicon

Heat(2000°C)SiO2

+2C

®

Si+2CO

SandCarbonMGSCarbonDioxideMGS(poly-silicon)with98%purity(1)首先由石英砂提煉成冶金級多晶矽

2023/6/617SiliconPurificationISi+HClTCS(vapor)

SiliconPowderHydrochlorideFiltersCondenserPurifierPureTCS(liquid)with99.9999999%Reactor,300C2023/6/618PolysiliconDeposition,EGS

Heat(1100°C)SiHCl3+H2

®

Si+3HCl

TCS(liquid)HydrogenEGSHydrochlorideEGS(Electronic-gradeSilicon)isalsopoly-silicon2023/6/619SiliconPurificationIILiquidTCSH2CarriergasbubblesH2andTCSProcessChamberTCS+H2EGS+HClEGS2023/6/620ElectronicGradeSiliconSource:/semiconductors/_polysilicon.html2023/6/621CrystalPullingMakeasingle-crystalsiliconingotCzochralski(CZ)methodFloatingZone(FZ)method2023/6/622CrystalPulling:CZmethodGraphiteCrucibleSingleCrystalsiliconIngotSingleCrystalSiliconSeedQuartzCrucibleHeatingCoils1415°CMoltenSilicon2023/6/623CZCrystalPullersMitsubishMaterialsSiliconSource:/semiconductors/_crystalgrowing.html2023/6/624CZCrystalPullingSource:/semiconductors/_crystalgrowing.html2023/6/625FloatingZoneMethodHeatingCoilsPolySiRodSingleCrystalSiliconSeedCrystalHeatingCoilsMovementMoltenSilicon2023/6/626ComparisonoftheTwoMethodsCZmethodismorepopularCheaperLargerwafersize(300mminproduction)ReusablematerialsFloatingZonePuresiliconcrystal(nocrucible)Moreexpensive,smallerwafersize(150mm)Mainlyforpowerdevices.2023/6/627IngotPolishing,Flat,orNotchFlat,150mmandsmallerNotch,200mmandlarger2023/6/628WaferSawingOrientationNotchCrystalIngotSawBladeDiamondCoatingCoolantIngotMovement2023/6/629ParametersofSiliconWaferWaferSize(mm)Thickness(mm)Area(cm2)Weight(grams)27920.261.3238145.614.0510052578.659.67125625112.7217.87150675176.7227.82200725314.1652,98300775706.21127.6250.8(2in)76.2(3in)2023/6/630WaferEdgeRounding(邊緣圓滑化)WaferWafermovementWaferBeforeEdgeRoundingWaferAfterEdgeRounding2023/6/631WaferLapping(粗磨拋光)Roughpolishedconventional,abrasive,slurry-lappingToremovemajorityofsurfacedamageTocreateaflatsurface2023/6/632WetEtchRemovedefectsfromwafersurface4:1:3mixtureofHNO3(79wt%inH2O),HF(49wt%inH2O),andpureCH3COOH.Chemicalreaction:3Si+4HNO3+18HF3H2SiF6+4NO+8H2O2023/6/633ChemicalMechanicalPolishing(CMP)SlurryPolishingPadPressureWaferHolderWafer2023/6/634200mmWaferThicknessandSurfaceRoughnessChanges76mm914mmAfterWaferSawingAfterEdgeRounding76mm914mm12.5mm814mm<2.5mm750mm725mmVirtuallyDefectFreeAfterLappingAfterEtchAfterCMP2023/6/635EpitaxyGrow(磊晶成長)DefinitionPurposesEpitaxyReactorsEpitaxyProcess2023/6/636Epitaxy:DefinitionGreekoriginepi:upontaxy:orderly,arrangedEpitaxiallayerisasinglecrystallayeronasinglecrystalsubstrate.2023/6/637Epitaxy:PurposeBarrierlayerforbipolartransistorReducecollectorresistancewhilekeephighbreakdownvoltage.Onlyavailablewithepitaxylayer.ImprovedeviceperformanceforCMOSandDRAMbecausemuchloweroxygen,carbonconcentrationthanthewafercrystal.2023/6/638EpitaxyApplication,BipolarTransistorn-Epipn+n+P-substrateElectronflown+BuriedLayerp+p+SiO2Al•Cu•SiBaseCollectorEmitter2023/6/639EpitaxyApplication:CMOSP-WaferN-WellP-WellSTIn+n+USGp+p+Metal1,Al•CuBPSGWP-typeEpitaxySilicon2023/6/640SingleCrystalSiliconEpitaxialLayerUseChemicalVaporDeposition(CVD)ChoosegasphaseepitaxyCanbedopedusingdopantgassource2023/6/641SiliconSourceGasesSilane

SiH4Dichlorosilane DCS SiH2Cl2Trichlorosilane TCS SiHCl3Tetrachlorosilane SiCl42023/6/642DopantSourceGasesDiborane B2H6Phosphine PH3Arsine AsH32023/6/643DCSEpitaxyGrow,ArsenicDoping

Heat(1100°C)SiH2Cl2

®

Si+2HClDCS EpiHydrochlorideAsH3®As+3/2H2

Heat(1100°C)2023/6/644SchematicofDCSEpiGrowandArsenicDopingProcessSiH2Cl2SiAsH3AsAsH3HHClH22023/6/645EpitaxialSiliconGrowthRateTrendsGrowthRate,micron/min1000/T(K)Temperature(°C)1.01.10.010.020.01.01300120011001000900800700SiH4SiH2Cl2SiHCl3SurfacereactionlimitedMasstransportlimited2023/6/646BarrelReactor

RadiationHeatingCoilsWafers2023/6/647VerticalReactorHeatingCoilsWafersReactantsReactantsandbyproducts2023/6/648HorizontalReactorHeatingCoilsWafersReactantsReactantsandbyproducts2023/6/649EpitaxyProcess,BatchSystemHydrogenpurge,temperaturerampupHClcleanEpitaxiallayergrowHydrogenpurge,temperaturecooldownNitrogenpurgeOpenChamber,waferunloading,reloading2023/6/650SingleWaferReactorHydrogenambientCapableformultiplechambersonamainframeLargewafersize(to300mm)Betteruniformitycontrol2023/6/651SingleWaferReactorHeatingLampsHeatRadiationWaferQuartzWindowReactantsReactants&byproductsQuartzLiftFingersSusceptor2023/6/652EpitaxyProcess,SingleWaferSystemHydrogenpurge,clean,temperaturerampupEpitaxiallayergrowHydrogenpurge,heatingpoweroffWaferunloading,reloadingIn-situHClclean2023/6/653WhyHydrogenPurgeMostsystemsusenitrogenaspurgegasNitrogenisaverystableabundantAt>1000C,N2canreactwithsiliconSiNonwafersurfaceaffectsepidepositionH2isusedforepitaxychamberpurgeCleanwafersurfacebyhydridesformation2