半导体测试技术复习

/“”‹zzzThedeviceseriesresistance,capacitance,thresholdvoltage,hotcarrierdegradationofMOSdevices,andotherparameters.zDiffusionandionimplantation•np,np•Two-pointprobe(1a)•four-pointprobe(1b)deviceundertest(DUT).(around1012ohmsorhigher)RWRCasKelvinmeasurements,afterLordKelvin.2PrbPc2323ohm·cmV:voltsIamperess:cm10mV4s=s1=s2=s330500m;0.5-1.5mm;If:s=0.1588cm,2s=1,then=V/IWAFERA.WAFERBWAFERmappingB.C.1.5m,=2sF·V/I(1.11)Fcorrectionfactors)2.1F‹‹FwaferF1tFornon-conductingbottomwafer:Forconductingbottomwafer:F1:F2,F31sheetresistance,Rsh):ohmspersquare?ohmspersquare2.2•VanDerPauw•2.3zzzzzzzzqnv,10mV.zsheetresistanceuniformitiesbetterthan1%FS1+1.082(1−s2/sm)zz/zzzz1010–1011ohms/square,1012zz3.Wafermapping•••wafermapping1970s•••MAPPINGmodulatedphotoreflectanceopticaldensitometry3.2ModulatedPhotoreflectancezzzzz1m,MAPPINGzz3.3CarrierIllumination(CIzModulatedPhotoreflectancez1z980nm)zzzzzOpticalDensitometryzMAPPINGz3.4OpticalDensitometryzzRESISTIVITYPROFILINGdopantdensityprofiles‹DifferentialHallEffect(DHE)‹SpreadingResistanceProfiling(SRP)‹capacitance-voltage‹secondaryionmassspectrometry.‹4RESISTIVITYPROFILING4.1DifferentialHallEffect(DHE)zremoving–measuring-removing-measuring)z(t−x)1.19z1.29non-conductingbottom‹‹Hall,SIMS)1/Rsh(x)vs.x1.301.311.32‹GaAs‹‹4.2SpreadingResistanceProfiling(SRP).z1960SzSRPz(1012–1021cm−3)znmz.SRP),R=2Rp+2Rc+2Rsp1.41zz10-203‹z100150100nm2025.zSRPz1-2m1–5‹0.5m0.5z5mand1,0.87nm.z5CONTACTLESSMETHODSzzz‹‹‹…5.1EddyCurrentz(eddycurrent)zzz5.2zWAFERHALL‹110‹‹¾¾10−3to103ohm-cm.Pnnp‹a)(b)(c)(b)d)•nVA=Vb+VD1VbV32VAVb•pV32VA0STRENGTHSANDWEAKNESSES:z‹WAFER‹‹z‹‹‹MappingDifferentialHallEffect:•‹•‹‹•:•‹‹‹‹‹•‹•:•‹100•‹‹‹metallayersonsemiconductor•:•‹‹‹•‹mapping‹‹•1.?•2.CHEMICALANDPHYSICALCHARACTERIZATIONzX-ray…1X-Y)2.1ScanningElectronMicroscopy(SEM)•SEM••2.2AugerElectronSpectroscopy(AES)••AugerAuger•Auger•Auger•Auger•Auger•.•Auger“O-J”effect),•••10–30keV•AugerAuger•Auger(Auger)•KLMN•AugerEfEvhvEKE1EK=E3-E2-E1-φE2E3φXAugerAuger12Auger()34Auger2.5(LowEnergyElectronDiffractionLEED)••••.zzz2.6(ElectronBeam-InducedCurrent(EBIC))•••.•EBIC“chargecollectionscanningelectronmicroscopy”‹1958EverhartSEM‹WellsMOSSEM‹LanderEBIC‹1965WittryEBICLτ•••.•EBIC-GBe-hpairsElectronbeamIEBICSchottkybarrierIIbIg2.7TransmissionElectronMicroscopy(TEM)••••••••Bragg.---•••••••••z‹OA(h1k1l1)OBBraggh1k1l1h1k1l1OA(h1k1l1)OBIO(hkl)IhklAIA=IO-IhklBIB=IOIA/IB=(IO-Ihkl)/IO————‹‹2.8SecondaryIonMassSpectroscopy(SIMS)••••.‹30Arnot‹1949HerzogViekbock‹‹.••••3.2RutherfordBackscatteringSpectrometry(RBS)RBSRBS•••(accuraciesof5%)•1017to1020cm−3,4X-RAYANDGAMMA-RAYTECHNIQUESzzz4.1x-X-rayfluorescence(XRF).applications—2θLiF(200)2θ=44.59—2θIr(Kα)Ir1Mo(Z42)KKα1Kα2Kβ1Kβ2Kβ31005014572Fe(Z=26)Cu(Z=29)Ag(Z=49)Kα11.9361.5400.559A5~92(1)(2)(3)—•ScanningElectronMicroscopy:Itsmajorstrengthliesinthehigh-resolutionandhighdepth-of-fieldcapabilityoftheinstrument.Ithasevolvedfromahighlyspecializedinstrumenttooneroutinelyusedtodayforline-widthmeasurements,forexample.Itsmajordisadvantageistheneedforavacuum,whichistrueforallelectronbeaminstruments.zAugerElectronSpectroscopy:Itsmajorstrengthistheabilitytocharacterizethinlayersforbothelementalandmolecularinformation.InscanningAES,theinstrumentprovideshigh-resolutionimages.Itsmajordisadvantagesaretheneedforhighvacuumanditsrelativelylowsensitivity.zElectronMicroprobe:ItsmajorstrengthistheavailabilityofEMPonmanyscanningelectronmicroscopesandtherelativelysimplewayofobtainingquantitativeelementalinformation.Theenergyresolutionofenergydispersivespectroscopyismodest,butusuallysufficient.Forhigherenergyresolutiononeneedstousewavelengthdispersivespectroscopy,whichismoredifficulttouse.Aweaknessisthemodestspatialresolutionofthetechniqueandthedamagetheelectronbeamcaninflictonsemiconductorsamples.zTransmissionElectronMicroscopy:Itsmajorstrengthliesinitsunprecedentedatomicresolutionimagingability.Toachievethis,onemustprepareextremelythinsamples,thereforemakingsamplepreparationitsmajorweakness.Thishasbeensomewhatalleviatedbyfocusedionbeamsamplepreparation.zSecondaryIonMassSpectrometry:Itsmajorstrengthliesinitssensitivity(betterthanmostbeamtechniques)andtheabilitytodetectallimpurities.Furthermore,itisoneofthemostcommonlyusedbeamtechniquesfordopantprofilingand,withtime-of-flightSIMS,fororganicandsurfacemetalcontaminants.Itsweaknessesincludematrixeffects,molecularinterferences,thedestructivenatureofthemeasurement,andtheneedforcalibratedsamples.zRutherfordBackscattering:Itsmajorstrengthliesinitscontactlessandabsolutemeasurementswithoutrecoursetocalibratedstandards.ItsmajorweaknessisthespecializednatureoftheinstrumentationandthedifficultyofmeasuringlightelementsonaheavyelementsubstratezX-RayFluorescence:Itmajorstrengthistheabilityforrapid,contactlesssurveyofelements.ItsweaknessisthemodestresolutionduetothedifficultyoffocusingX-raysandthepresenceofmatrixeffects.ThesensitivitytosurfacecontaminationisgreatlyextendedbytotalreflectionX-rayfluorescence.X-RayPhotoelectronSpectroscopy:Itmajorstrengthistheabilitytocharacterizetheelementalandmolecularna