晶圆制造专题知识市公开课金奖市赛课一等奖课件

Chapter4

WaferManufacturingandEpitaxyGrowing/10/101第1页CrystalStructuresAmorphousNorepeatedstructureatallPolycrystallineSomerepeatedstructuresSinglecrystalOnerepeatedstructure/10/102第2页AmorphousStructure/10/103第3页PolycrystallineStructureGrainGrainBoundary/10/104第4页SingleCrystalStructure/10/105第5页WhySilicon?Abundant,cheapSilicondioxideisverystable,strongdielectric,anditiseasytogrowinthermalprocess.Largebandgap,wideoperationtemperaturerange./10/106第6页Source:http://www.shef.ac.uk/chemistry/web-elements/nofr-key/Si.html/10/107第7页UnitCellofSingleCrystalSilicon/10/108第8页CrystalOrientations:<100>xyz<100>plane/10/109第9页CrystalOrientations:<111>xyz<100>plane<111>plane/10/1010第10页CrystalOrientations:<110>xyz<110>plane/10/1011第11页<100>OrientationPlaneAtomBasiclatticecell/10/1012第12页<111>OrientationPlaneSiliconatomBasiclatticecell/10/1013第13页IllustrationofthePointDefectsSiliconAtomImpurityonsubstitutionalsiteFrenkelDefectVacancy(空位)orSchottkyDefectImpurityinInterstitialSiteSiliconInterstitial間隙/10/1014第14页DislocationDefects/10/1015第15页FromSandtoWaferQuartzsand:silicondioxideSandtometallicgradesilicon(MGS)ReactMGSpowderwithHCltoformTCSPurifyTCSbyvaporizationandcondensationReactTCStoH2toformpolysilicon(EGS)MeltEGSandpullsinglecrystalingot/10/1016第16页FromSandtoWafer(cont.)Cutend,polishside,andmakenotchorflatSawingotintowafersEdgerounding,lap,wetetch,andCMPLaserscribeEpitaxydeposition/10/1017第17页晶圓形成之步驟

FromSandtoSilicon

Heat(°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

/10/1018第18页SiliconPurificationISi+HClTCS(vapor)

SiliconPowderHydrochlorideFiltersCondenserPurifierPureTCS(liquid)with99.9999999%Reactor,300C/10/1019第19页PolysiliconDeposition,EGS

Heat(1100°C)SiHCl3+H2

®

Si+3HCl

TCS(liquid)HydrogenEGSHydrochlorideEGS(Electronic-gradeSilicon)isalsopoly-silicon/10/1020第20页SiliconPurificationIILiquidTCSH2CarriergasbubblesH2andTCSProcessChamberTCS+H2EGS+HClEGS/10/1021第21页ElectronicGradeSiliconSource:/semiconductors/_polysilicon.html/10/1022第22页CrystalPullingMakeasingle-crystalsiliconingotCzochralski(CZ)methodFloatingZone(FZ)method/10/1023第23页CrystalPulling:CZmethodGraphiteCrucibleSingleCrystalsiliconIngotSingleCrystalSiliconSeedQuartzCrucibleHeatingCoils1415°CMoltenSilicon/10/1024第24页CZCrystalPullersMitsubishMaterialsSiliconSource:/semiconductors/_crystalgrowing.html/10/1025第25页CZCrystalPullingSource:/semiconductors/_crystalgrowing.html/10/1026第26页FloatingZoneMethodHeatingCoilsPolySiRodSingleCrystalSiliconSeedCrystalHeatingCoilsMovementMoltenSilicon/10/1027第27页ComparisonoftheTwoMethodsCZmethodismorepopularCheaperLargerwafersize(300mminproduction)ReusablematerialsFloatingZonePuresiliconcrystal(nocrucible)Moreexpensive,smallerwafersize(150mm)Mainlyforpowerdevices./10/1028第28页IngotPolishing,Flat,orNotchFlat,150mmandsmallerNotch,200mmandlarger/10/1029第29页WaferSawingOrientationNotchCrystalIngotSawBladeDiamondCoatingCoolantIngotMovement/10/1030第30页ParametersofSiliconWaferWaferSize(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)/10/1031第31页WaferEdgeRounding(邊緣圓滑化)WaferWafermovementWaferBeforeEdgeRoundingWaferAfterEdgeRounding/10/1032第32页WaferLapping(粗磨拋光)Roughpolishedconventional,abrasive,slurry-lappingToremovemajorityofsurfacedamageTocreateaflatsurface/10/1033第33页WetEtchRemovedefectsfromwafersurface4:1:3mixtureofHNO3(79wt%inH2O),HF(49wt%inH2O),andpureCH3COOH.Chemicalreaction:3Si+4HNO3+18HF3H2SiF6+4NO+8H2O/10/1034第34页ChemicalMechanicalPolishing(CMP)SlurryPolishingPadPressureWaferHolderWafer/10/1035第35页200mmWaferThicknessandSurfaceRoughnessChanges76mm914mmAfterWaferSawingAfterEdgeRounding76mm914mm12.5mm814mm<2.5mm750mm725mmVirtuallyDefectFreeAfterLappingAfterEtchAfterCMP/10/1036第36页EpitaxyGrow(磊晶成長)DefinitionPurposesEpitaxyReactorsEpitaxyProcess/10/1037第37页Epitaxy:DefinitionGreekoriginepi:upontaxy:orderly,arrangedEpitaxiallayerisasinglecrystallayeronasinglecrystalsubstrate./10/1038第38页Epitaxy:PurposeBarrierlayerforbipolartransistorReducecollectorresistancewhilekeephighbreakdownvoltage.Onlyavailablewithepitaxylayer.ImprovedeviceperformanceforCMOSandDRAMbecausemuchloweroxygen,carbonconcentrationthanthewafercrystal./10/1039第39页EpitaxyApplication,BipolarTransistorn-Epipn+n+P-substrateElectronflown+BuriedLayerp+p+SiO2Al•Cu•SiBaseCollectorEmitter/10/1040第40页EpitaxyApplication:CMOSP-WaferN-WellP-WellSTIn+n+USGp+p+Metal1,Al•CuBPSGWP-typeEpitaxySilicon/10/1041第41页SingleCrystalSiliconEpitaxialLayerUseChemicalVaporDeposition(CVD)ChoosegasphaseepitaxyCanbedopedusingdopantgassource/10/1042第42页SiliconSourceGasesSilane

SiH4Dichlorosilane DCS SiH2Cl2Trichlorosilane TCS SiHCl3Tetrachlorosilane SiCl4/10/1043第43页DopantSourceGasesDiborane B2H6Phosphine PH3Arsine AsH3/10/1044第44页DCSEpitaxyGrow,ArsenicDoping

Heat(1100°C)SiH2Cl2

®

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

Heat(1100°C)/10/1045第45页SchematicofDCSEpiGrowandArsenicDopingProcessSiH2Cl2SiAsH3AsAsH3HHClH2/10/1046第46页EpitaxialSiliconGrowthRateTrendsGrowthRate,micron/min1000/T(K)Temperature(°C)1.01.10.010.020.01.01300120011001000900800700SiH4SiH2Cl2SiHCl3SurfacereactionlimitedMasstransportlimited/10/1047第47页BarrelReactor

RadiationHeatingCoilsWafers/10/1048第48页VerticalReactorHeatingCoilsWafersReactantsReactantsandbyproducts/10/1049第49页HorizontalReactorHeatingCoilsWafersReactantsReactantsandbyproducts/10/1050第50页EpitaxyProcess,BatchSystemHydrogenpurge,temperaturerampupHClcleanEpitaxiallayergrowHydrogenpurge,temperaturecooldownNitrogenpurgeOpenChamber,waferunloading,reloading/10/1051第51页SingleWaferReactorHydrogenambientCapableformultiplechambersonamainframeLargewafersize(to300mm)Betteruniformitycontrol/10/1052第52页SingleWaferReactorHeatingLampsHeatRadiationWaferQuartzWindowReactantsReactants&byproductsQuartzLiftFingersSusceptor/10/1053第53页EpitaxyProcess,SingleWaferSystemHydrogenpurge,clean,temperaturerampupEpitaxiallayergrowHydrogenpurge,heatingpoweroffWaferunloading,reloadingIn-situHClclean/10/1054第54页WhyHydrogenPurgeMostsystemsusenitrogenaspurgegasNitrogenisaverystableabundantAt>1000C,N2canreactwithsiliconSiNonwafersurfaceaffectsepidepositionH2isusedforepitaxychamberpurgeCleanwafersurfacebyhydridesformat