SMT-10OxidationCD

,SemiconductorManufacturingTechnologyMichaelQuirk&JulianSerdaOctober2001byPrenticeHallChapter10Oxidation,2000byPrenticeHall,SemiconductorManufacturingTechnologybyMichaelQuirkandJulianSerda,Objectives,Afterstudyingthematerialinthischapter,youwillbeableto:1.Describeanoxidefilmforsemiconductormanufacturing,includingitsatomicstructure,howitisusedanditsbenefits.2.Statethechemicalreactionforoxidationanddescribehowoxidegrowsonsilicon.3.Explainselectiveoxidationandgivetwoexamples.4.Statethethreetypesofthermalprocessingequipment,describethefivepartsofaverticalfurnace,andgivetheattributesofafastrampverticalfurnace.5.Explainwhatisarapidthermalprocessor,itsusageanddesign.6.Describethecriticalaspectsoftheoxidationprocess,itsqualitymeasuresandsomecommontroubleshootingproblems.,DiffusionAreaofWaferFabrication,UsedwithpermissionfromAdvancedMicroDevices,Figure10.1,OxideFilm,NatureofOxideFilmUsesofOxideFilmDeviceProtectionandIsolationSurfacePassivationGateOxideDielectricDopantBarrierDielectricBetweenMetalLayers,AtomicStructureofSiliconDioxide,UsedwithpermissionfromInternationalSEMATECH,Figure10.2,FieldOxideLayer,Figure10.3,GateOxideDielectric,Figure10.4,OxideLayerDopantBarrier,Figure10.5,Table10.1OxideApplications:NativeOxide,Table10.1A,Table10.1OxideApplications:FieldOxide,Table10.1B,Table10.1OxideApplications:GateOxide,Purpose:Servesasadielectricbetweenthegateandsource-drainpartsofMOStransistor.,Comments:Growthrateatroomtemperatureis15perhouruptoabout40.Commongateoxidefilmthicknessrangefromabout30to500.Dryoxidationisthepreferredmethod.,Table10.1C,Table10.1OxideApplications:BarrierOxide,Table10.1D,Table10.1OxideApplications:DopantBarrier,Table10.1E,Table10.1OxideApplications:PadOxide,Table10.1F,Table10.1OxideApplications:ImplantScreenOxide,Table10.1G,Table10.1OxideApplications:InsulatingBarrierbetweenMetalLayers,Table10.1H,ThermalOxidationGrowth,ChemicalReactionforOxidationDryoxidationWetoxidationOxidationGrowthModelOxidesiliconinterfaceUseofchlorinatedagentsinoxidationRateofoxidegrowthFactorsaffectingoxidegrowthInitialgrowthphaseSelectiveoxidationLOCOSSTI,OxideThicknessRangesforVariousRequirements,Table10.2,DryOxidationTime(Minutes),Figure10.6,WetOxygenOxidation,Figure10.7,ConsumptionofSiliconduringOxidation,Figure10.8,Liquid-StateDiffusion,Figure10.9,ChargeBuildupatSi/SiO2Interface,UsedwithpermissionfromInternationalSEMATECH,Figure10.10,DiffusionofOxygenThroughOxideLayer,Figure10.11,Linear&ParabolicStagesforDryOxidationGrowthat1100C,UsedwithpermissionfromInternationalSEMATECH,Figure10.12,LOCOSProcess,Figure10.13,SelectiveOxidationandBirdsBeakEffect,UsedwithpermissionfromInternationalSEMATECH,Figure10.14,STIOxideLiner,Figure10.15,FurnaceEquipment,HorizontalFurnaceVerticalFurnaceRapidThermalProcessor(RTP),HorizontalandVerticalFurnaces,Table10.3,HorizontalDiffusionFurnace,PhotographcourtesyofInternationalSEMATECH,Photo10.1,VerticalDiffusionFurnace,PhotographcourtesyofInternationalSEMATECH,Photo10.2,BlockDiagramofVerticalFurnaceSystem,Figure10.16,VerticalFurnaceProcessTube,Figure10.17,HeaterElementPowerDistribution,UsedwithpermissionfromInternationalSEMATECH,Figure10.18,LocationsofThermocouplesintheFurnaceChamber,Figure10.19,CommonGasesusedinFurnaceProcesses,Table10.4,BurnBoxtoCombustExhaust,UsedwithpermissionfromInternationalSEMATECH,Figure10.20,ThermalProfileofConventionalVersusFastRampVerticalFurnace,ReprintedfromtheJune1996editionofSolidStateTechnology,copyright1996byPennWellPublishingCompany.,Figure10.21,FastRamp,Conventional,TheMainAdvantagesofaRapidThermalProcessor,ReducedthermalbudgetMinimizeddopantmovementinthesiliconEaseofclusteringmultipletoolsReducedcontaminationduetocoldwallheatingCleanerambientbecauseofthesmallerchambervolumeShortertimetoprocessawafer(referredtoascycletime),ComparisonofConventionalVerticalFurnaceandRTP,Table10.5,RapidThermalProcessor,Figure10.22,RapidThermalProcessor,PhotographcourtesyofAdvancedMicroDevices,AppliedMaterials5300CenturaRTP,Photo10.3,RTPApplications,AnnealofimplantstoremovedefectsandactivateanddiffusedopantsDensificationofdepositedfilms,suchasdepositedoxidelayersBorophosphosilicateglass(BPSG)reflowAnnealofbarrierlayers,suchastitaniumnitride(TiN)Silicideformation,suchastitaniumsilicide(TiSi2)Contactalloying,OxidationProcess,PreOxidationCleaningOxidationprocessrecipeQualityMeasurementsOxidationTroubleshooting,CriticalIssuesforMinimizingContamination,Maintenanceofthefurnaceandassociatedequipment(especiallyquartzcomponents)forcleanlinessPurityofprocessingchemicalsPurityofoxidizingambient(thesourceofoxygeninthefurnace)Wafercleaningandhandlingpractices,ThermalOxidationProcessFlowChart,Figure10.23,ProcessRecipeforDryOxidationPr