Semiconductor Device and Material Characterization

ECE4813Dr.AlanDoolittleECE4813SemiconductorDeviceandMaterialCharacterizationDr.AlanDoolittleSchoolofElectricalandComputerEngineeringGeorgiaInstituteofTechnologyAswithalloftheselectureslides,IamindebtedtoDr.DieterSchroderfromArizonaStateUniversityforhisgenerouscontributionsandfreelygivenresources.Mostof(80%)thefigures/slidesinthislecturecamefromDieter.Someofthesefiguresarecopyrightedandcanbefoundwithintheclasstext,SemiconductorDeviceandMaterialsCharacterization.Everyseriousmicroelectronicsstudentshouldhaveacopyofthisbook!ECE4813Dr.AlanDoolittleDefectsTypesofDefectsDefectEtchingGeneration–RecombinationCapacitanceTransientsDeepLevelTransientSpectroscopyECE4813Dr.AlanDoolittleDefectsandYieldInterstitialOxygenVacanciesSelfInterstitialsMetalImpuritiesRecombinationCentersMetalPrecipitatesDislocationsStackingFaultsPrecipitatesDRAMRefreshFailuresLeakyJunctionsOxideBreakdownBipolarTrans.PipesYield$ECE4813Dr.AlanDoolittleWaferDefectsBulkSiOxygenParticles,ScratchesMetalsDopantsMetalsRoughnessCOPstDenudedLayerPrecipitatedSubstratePrecipitatesDenudedSiEpiLayerHeavilyDopedSubstratetxxDefectsEpitaxialSiCOPs(CrystalOriginatedPits)ECE4813Dr.AlanDoolittleDefectTypesParticlesResiduesOrganicsLightMetalsAlkaliMetals,e.g.,NaMetalsCu*,Fe*,Cr*,Ni*,Zn,Ca,Al(*Mostimportant?)CrystalOriginatedPits(COPs)SurfaceRoughnessECE4813Dr.AlanDoolittleDefectSourcesSiliconStartingMaterialSiliconGrowthWaferSawing,PolishingWaferPackaging,ShippingWaferCleaningLiquids,GasesOxidation,DiffusionPhotoresistIonImplantationSputterDepositionProcessEquipmentEpitaxialGrowthReactiveIonEtchingPolymerContainers/PipesDoorHingesLightSwitchesBallBearingsPeopleECE4813Dr.AlanDoolittlePointDefectsECE4813Dr.AlanDoolittleLine,Plane,VolumeDefectsECE4813Dr.AlanDoolittleStackingFaultsOxidation-inducedSFs:SiinterstitialsaregeneratedduringoxidationandforcedintothesubstrateSFscanalsobegeneratedatsubstrate/epiinterfacesSiOxideSiInterstitialsAtomplanes(111)Si(100)SiTopViewSFinGaAsNECE4813Dr.AlanDoolittleDefectEtchingCertainetchesattackdefectiveregionsallowingdefectidentification(etchrecipesgivenatendofnotes)D.C.MillerandG.A.Rozgonyi,“DefectCharacterizationbyEtching,OpticalMicroscopy,andX-RayTopography,”inHandbookonSemiconductors3(S.P.Keller,ed.)North-Holland,Amsterdam,1980,217-246.ASTMStandardsF47andF26,1997AnnualBookofASTMStandards,Am.Soc.Test.Mat.,WestConshohocken,PA,1997.ECE4813Dr.AlanDoolittleDefectEtchingDifferentetchesattackdefectiveregionsdifferentlyCanbeaccentuatedthroughcopperdecorationSeccoWrightADefects:HF+HNO3ADefects:HF+HNO3+H3PO4ADefects-InterstitialsSeccoWrightHF+HNO3HF+HNO3+H3PO41.25mmDDefects-VacanciesMicrographscourtesyofM.S.Kulkarni,MEMC(J.Electrochem.Soc.149,G153,Feb.2002)ECE4813Dr.AlanDoolittleDefectEtchReferences[1]E.SirtlandA.Adler,“ChromicAcid-HydrofluoricAcidasSpecificReagentsfortheDevelopmentofEtchingPitsinSilicon,”Z.Metallkd.52,529-534,Aug.1961.[2]W.C.Dash,“CopperPrecipitationonDislocationsinSilicon,”J.Appl.Phys.27,1193-1195,Oct.1956;“EvidenceofDislocationJogsinDeformedSilicon,”J.Appl.Phys.29,705-709,April1958.[3]F.Seccod'Aragona,“DislocationEtchfor(100)PlanesinSilicon,”J.Electrochem.Soc.119,948-951,July1972.[4]D.G.Schimmel,“DefectEtchfor100SiliconIngotEvaluation,”J.Electrochem.Soc.126,479-483,March1979;D.G.SchimmelandM.J.Elkind,“AnExaminationoftheChemicalStainingofSilicon,”J.Electrochem.Soc.125,152-155,Jan.1978.[5]M.W.Jenkins,“ANewPreferentialEtchforDefectsinSiliconCrystals,”J.Electrochem.Soc.124,757-762,May1977.[6]K.H.Yang,“AnEtchforDelineationofDefectsinSilicon,”J.Electrochem.Soc.131,1140-1145,May1984.[7]H.Seiter,“IntegrationalEtchingMethods,”inSemiconductorSilicon/1977(H.R.HuffandE.Sirtl,eds.),Electrochem.Soc.,Princeton,NJ,1977,pp.187-195.[8]K.GraffandP.Heim,“Chromium-FreeEtchforRevealingandDistinguishingMetalContaminationDefectsinSilicon,”J.Electrochem.Soc.141,2821-2825,Oct.1994.[9]M.Ishii,R.Hirano,H.KanandAIto,“EtchPitObservationofVeryThin{001}-GaAsLayerbyMoltenKOH,”Japan.J.Appl.Phys.15,645-650,April1976;foramoredetaileddiscussionofGaAsEtchingseeD.J.StirlandandB.W.Straughan,“AReviewofEtchingandDefectCharacterisationofGalliumArsenideSubstrateMaterial,”ThinSolidFilms31,139-170,Jan.1976.[10]D.T.C.Huo,J.D.Wynn,M.Y.FanandD.P.Witt,“InPEtchPitMorphologiesRevealedbyNovelHCl-BasedEtchants,”J.Electrochem.Soc.136,1804-1806,June1989.ECE4813Dr.AlanDoolittleImpuritiesorDefectsShallow-levelimpurities(dopants)-measureopticallyPhotoluminescencePhotoelectronspectroscopyDeep-levelimpurities(metals)-measureelectricallyDeepleveltransientspectroscopy(DLTS)NeedtodetermineImpuritydensity,NTImpurityenergylevel,ETCaptureCrosssectionσTEcEvETShallow-levelImpuritiesDeep-levelImpuritiesSiDopantMetalECE4813Dr.AlanDoolittleGeneration-RecombinationConsiderasemiconductorwithadeep-levelimpurityatenergyE=ETElectronsandholescanbecapturedandemittedCaptureischaracterizedbythecapturecoefficientscn&cpcn=σnvthwhereσnisthecapturecrosssection[cm2]andvthisthethermalvelocityofelectrons.Similarlyforholes.Emissionischaracterizedbyemissionratesen