WAT-Introduction-(Andy)PPT课件

WaferAcceptanceTestIntroduction,Content,BriefideasofWATSystemintroduction(Hardware)TestEnvironment(Software)TestStructuresandTestMethodJudgement&DatareportConnectionwithEDA,BriefideasofWAT,PurposeofWAT,WAT:Totestparametersofdevicesintestkeyswhicharemadeinscribeline.Tobasicallydefineprocesscontrolstatusandprovidethedataforimprovingprocess.TestingdatashouldmeetcustomerPCMspec.,Testkey,Testkey:Agroupofdeviceswhicharemadeinanarea.Thereareseveraltestkeys(Eg.7)inadie.Eachtestkeyhasitsownnameandcontainsdifferentdevices.Everytestkeyhassamepads.Testkeysineverydiesarethesame.,Examples：,Scribeline,Scribeline:TheStreetbetweendies(chips).,TestStructures(Devices),TestkeyStructures,1.Transistor,3.Resistance,5.Junction,4.GoxIntegrity,2.Isolaton,4terminaldevices,Cont./ViaResistance,SheetResistance,6.Others,STI,MOSCapacitance,ActivetoWellJunction,Systemintroduction(Hardware),WATSystemConfiguration,MainPartsofWATSystemTesterCabinetTestheadProbecardProbestation,SystemBlockDiagram(4072A),SwitchMatrix,ProbeCard,Thispartactsasconnectorbetweentesterandprober,andtransfersthesignalsfromtestheadtothedevicetobetestedinthewafer.Totransferthesignalscorrectly,theremustbelittleleakageamongthepins.,ProbeStation,AmachinetotransferwaferbyMicrons,itcanmakethedeviceconnectedwiththepinsofprobecardbymovingthewaferaccurately.Beforetesting,wafercassettemustbeloadintothestageofprober,Peoplealsomustmakeprogramwhichleadthemachinetomakecorrectconnectionbetweentheprobepinsandtestkey,TestSystem,TestEnvironment(Software),HP-UXEnvironment,MeasurementProgrammingStyle,5PointsMeasurement,InWATarea,everywafermustbetested5points,Howtoperformtesting,SelectwaferSelectdieSelecttestkey(Module)Selectdevicemakeconnects,Beforetestingwemustfindthedevicetobetested,Soweshouldmakeatestplanwhichdoesactionsabove.,TestPlanSummary,Wafer,Module,Device,ATestPlancontainsinformationaboutdevicetestsforawafer.EachsetofinformationiscalledaSpec.,TestPlan,WaferSpec,ProbeSpec,TestSpec,DieSpec,WhatisaTestPlan?,DieXsize(STEPX),WaferDiameter(SIZE),1,2,3,4,5,6,7,1,2,3,4,5,6,7,x,y,Definitionofanexamplewafer,CenterDie,WaferSpecParameters,DieYsize(STEPY),AlignDie,BmoduleAmodule,Definitionofdieinanexamplewafer,Alignmodule,(0,0),(0,600),(0,300),(0,0)isspecifiedbyALIGNMODXandALIGNMODYinWaferSpecAttribute.,DieSpecParameters,Definitionofexampleprobecard,6,5,4,3,1,2,7,12,11,10,9,8,48,44,40,36,32,28,24,20,16,12,8,4,SWMPinNumber,ProbeSpecParameters,DefinedItemsNamesofdevicesinmodulesPadnumbersofdeviceAlgorithmnametobeusedforadeviceInput/Outputparametersvaluesforalgorithm,TestSpecParameters,Selects/Unselectsthedie/modulestotest,Toselectdieandmodulestotest,Showstheelapsedorremainingtime,Showsthetestdata,Cassettemapshowsthewaferstatus,Wafermapshowsthediestatus,ExecuteTestpanel,Liststhetestresultbyawafer,ClickonStartRetesttoretesttheselectedwafers,Selectwaferstotestagain,TestResultpanel,TestStructuresandTestMethod,CategoriesofTestStructures,TestkeyStructures,1.Transistor,3.Resistance,5.Junction,4.GoxIntegrity,2.Isolaton,4terminaldevices,Cont./ViaResistance,SheetResistance,6.Others,STI,MOSCapacitance,ActivetoWellJunction,WATTESTCONDITION,Transistor,MOSFET,ThresholdVoltage,在LinearRegion下，此直线交VGS轴于（，0)处。由于VDS=0.1V在VGSVT时，可得则因为VGS不断的增加，导致载流子在表面受到Scattering的几率大增，因而使得载子的AverageMobility大幅下降，所以Gm的最大值将会发生在附近。事实上，此最大值发生在处，亦即是饱和区与线性区的交界处。所以我们可以利用这个最大值，来找到操作在线性区下的这条ID-VGS直线，利用此直线来找到ID-VGS值。,VT=L1X-VD/2,(Max.SlopeMethod),FasterMeasurementofVT,MOSSaturationCurrent,Ids,Factors:VTGox,SubstrateCurrent,Vgs(V),Isub(A),ID(A),Testconditions:,(0-2.5V),Isub,MOSBreakdownCharacteristics,3.Zenerbreakdown,Isolation,IsolationDevice(PolyGate),SheetResistance,StraightResistor,W,100um,2terminal,SheetResistance,Rs,Ohmiclaw:Bulkresistance,R=(/Xj)(L/W):bulkresistivityL.W:squarenumber,L.W=L/WRs=/Xj=RW/L(ohm/square),Contact&ViaResistance,Rc,GateOxide&capacitancemeasurement,GateOxide&capacitancemeasurement,Capacitanceisverycriticalmeasurement，and,WecancalculatethethicknessofgateoxidebyCs,Junction,ContinuousandBridgecheck,Judgement&Datareport,KeyParameters,JudgementshouldbedonebaseonKeyParameters.KeyParametersmustbedefinedbyGSMCandCustomer.,Numerator,Denominator,Pass,Fail,Invalid,Setpass/failconditionforeachitemUserBinnumberisusedasNumeratorandDenominatorNumeratorandDenominatorsetpass/fail/invalidjudgmentcondition,Fail,Invalid,ItemJudgement,SettargetpassrateofeachitemUsedtojudgethesameitemsinthewaferPassrateiscalculatedasfollow:PasscountPasscount+FailcountItemisjudgedfailwhenthepassrateislessthantheTgtvalue.,*100%,Example,ItemA,PassRate:,45,*100=80(%),TargetParameter,Judgeafterallitemsaremeasured.,35,*100=60(%)ConformingItemRate,PassRate:,DieisjudgedFAIL,ConformingItemRate=80%,DieJudgment,WaferisjudgebyItempassrateandDiepassrateItemisjudgedusingYield(N/D)andTGTparameterintheLimitFile.,PassRateof“ItemA”:,35,*100=60(%)TGT,TGT=80%,“ItemA”isjudgedFAIL,WaferJudgmentbyItem,Judgeafteralldieismeasured.,WaferJudgmentbyItem,ConformingItemRate=90%,34,*100=75(%)ConfirmingItemRate,ItemRate:,WaferFail,80%(4/5)Pass,80%(4/5)Pass,80%(4/5)Pass,60%(3/5)Fail(TGT),PassRateofeachitem(UseTGT),TGT=80%,Judgeafteralldieismeasured.,WaferisjudgedFAIL,ConformingDieRate=80%,WaferJudgmentbydie,ConformingItemRate=90%,DiePassRate:,35,*100=60(%)ConfirmingItemRate,Judgeafterallwaferismeasured.,LotisjudgedFAIL,ConformingWaferRate=90%,LotJudgment,WaferPassRate:,2025,*100=80(%)ConfirmingItemRate,Tosetpass/failjudgmentcondition,WATDataReport,Summary,Detial,Engineer,ConnectionwithEDA,YieldManagementBackbone,WIP,ToolProcessParameters,Design,FAManufacturingExecutionSystems,OtherDataSources,WaferFab,TestFloor,OtherDataSources,OfficeDesktop,MES,WaferFab,TestFloor,TheEnd,WATHoldRule,Holdanywaferthathasfailsites3(mustbe)Holdalotwhenfailwafers4Holdalotwhensameparameterfail10%sitesHoldalotifitviolateuserdefinedholdrules(internalrequirement)OtherrequirementfromcustomerHoldalotwhensamesitesfail25%(customerrequirement)Product80%passrate(customerrequirement),Tester,The