SMT-10OxidationCD

©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaSemiconductorManufacturingTechnologyMichaelQuirk&JulianSerda©October2001byPrenticeHallChapter10Oxidation©2000byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerda©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaObjectivesAfterstudyingthematerialinthischapter,youwillbeableto:1.Describeanoxidefilmforsemiconductormanufacturing,includingitsatomicstructure,howitisusedanditsbenefits.2.Statethechemicalreactionforoxidationanddescribehowoxidegrowsonsilicon.3.Explainselectiveoxidationandgivetwoexamples.4.Statethethreetypesofthermalprocessingequipment,describethefivepartsofaverticalfurnace,andgivetheattributesofafastrampverticalfurnace.5.Explainwhatisarapidthermalprocessor,itsusageanddesign.6.Describethecriticalaspectsoftheoxidationprocess,itsqualitymeasuresandsomecommontroubleshootingproblems.©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaDiffusionAreaofWaferFabricationTest/SortThinFilmsImplantDiffusionEtchPolishPhotoCompletedwaferWaferfabrication(front-end)UnpatternedwaferWaferstartUsedwithpermissionfromAdvancedMicroDevicesFigure10.1©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaOxideFilm•NatureofOxideFilm•UsesofOxideFilm–DeviceProtectionandIsolation–SurfacePassivation–GateOxideDielectric–DopantBarrier–DielectricBetweenMetalLayers©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaAtomicStructureofSiliconDioxideSiliconOxygenUsedwithpermissionfromInternationalSEMATECHFigure10.2©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaFieldOxideLayerp+Siliconsubstratep-Epitaxiallayern-wellp-wellFieldoxideisolatesactiveregionsfromeachother.Figure10.3©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaGateOxideDielectricGateOxidep+Siliconsubstratep-Epitaxiallayern-wellp-wellPolysilicongateFigure10.4©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaOxideLayerDopantBarrierPhosphorusimplantp+Siliconsubstratep-Epitaxiallayern-wellBarrieroxideFigure10.5©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaTable10.1OxideApplications:NativeOxidePurpose:Thisoxideisacontaminantandgenerallyundesirable.Sometimesusedinmemorystorageorfilmpassivation.Comments:Growthrateatroomtemperatureis15perhouruptoabout40Å.p+SiliconsubstrateSilicondioxide(oxide)Table10.1A©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaTable10.1OxideApplications:FieldOxidePurpose:Servesasanisolationbarrierbetweenindividualtransistorstoisolatethemfromeachother.Comments:Commonfieldoxidethicknessrangefrom2,500Åto15,000Å.Wetoxidationisthepreferredmethod.FieldoxideTransistorsitep+SiliconsubstrateTable10.1B©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaTable10.1OxideApplications:GateOxidePurpose:Servesasadielectricbetweenthegateandsource-drainpartsofMOStransistor.Comments:Growthrateatroomtemperatureis15Åperhouruptoabout40Å.Commongateoxidefilmthicknessrangefromabout30Åto500Å.Dryoxidationisthepreferredmethod.GateoxideTransistorsitep+SiliconsubstrateSourceDrainGateTable10.1C©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaTable10.1OxideApplications:BarrierOxidePurpose:Protectactivedevicesandsiliconfromfollow-onprocessing.Comments:ThermallygrowntoseveralhundredAngstromsthickness.BarrieroxideDiffusedresistorsMetalp+SiliconsubstrateTable10.1D©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaTable10.1OxideApplications:DopantBarrierPurpose:Maskingmaterialwhenimplantingdopantintowafer.Example:Spaceroxideusedduringtheimplantofdopantintothesourceanddrainregions.Comments:Dopantsdiffuseintounmaskedareasofsiliconbyselectivediffusion.DopantbarrierspaceroxideIonimplantationGateSpaceroxideprotectsnarrowchannelfromhigh-energyimplantTable10.1E©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaTable10.1OxideApplications:PadOxidePurpose:ProvidesstressreductionforSi3N4Comments:Thermallygrownandverythin.PassivationLayerILD-4ILD-5M-3M-4PadoxideBondingpadmetalNitrideTable10.1F©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaTable10.1OxideApplications:ImplantScreenOxidePurpose:Sometimesreferredtoas“sacrificialoxide”,screenoxide,isusedtoreduceimplantchannelinganddamage.Assistscreationofshallowjunctions.Comments:ThermallygrownIonimplantationScreenoxideHighdamagetoupperSisurface+morechannelingLowdamagetoupperSisurface+lesschannelingp+SiliconsubstrateTable10.1G©2001byPrenticeHallSemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerdaPassivationlayerILD-4ILD-5M-3M-4InterlayeroxideBondingpadmetalTable10.1OxideApplications:InsulatingBarrierbetweenMetalLayersPurpose:Servesasprotectivelayerbetweenmetallines.Comments:Thisoxideisnotthermallyg