WAT-Basic-IntroductionPPT课件

-,1,WATBasicIntroduction,-,2,Summary,WhatisWAT?WhydoweneedWAT?WhatcanandcantWATdo?WATbasicconcept/device/LayoutManualWATprobe(4156)Q&A,-,3,WhatisWAT?,WATisabbreviationforWaferAcceptanceTest.WATisthelastprocessinFAB.WATisanimportantprocessinFAB.decidewhetherthewafergothroughannormalprocess,andshiptocustomer.,-,4,-,5,WhydoweneedWAT?,WATcantestindividualdeviceofstreet,notdieorchip.WATcancheckelectriccharactersofindividualdevice.WATcanmonitorfrontprocessviaelectriccharactersofindividualdevice.WATcanprovideoutdevicetestdataforconsumer.,-,6,WhatcanandcantWATdo?,-,7,WhatcanandcantWATdo?.cont,-,8,Testpattern:1)TestLine/TestKey:Productionmonitor,locatedontheScribeLineandwillbedestroyedafterdiesaw.2)TestChip:DesignRulecheck/Yieldmonitor/ProcessQualification,usuallychipsize,forinitialprocesstechnologydevelopment.,WATbasicconcept/device/layout,-,9,WATbasicconcept/device/layout.cont,-,10,WATbasicconcept/device/layout.cont,MOSkeyparameters:VtandGmIdsatIoffVBDIsubDIBLGAMMASWINGGleak,Isubmax,Isubvg,Gleak2,SUBVTSLP,Vt1,Vt2,MFAC1,MFAC2,BETA,-,11,TypicalWATtestkeylayout,-,12,DeviceparameterMOS,Purpose:checktransistorelectricalcharacter.,-,13,ContinuityandSpacingofPoly,Metal,Spacing/Bridging.StepincreaseVoltage,Breakdown1uAleakagecurrent,-,14,FieldDevice,Purpose:CheckfiledIsolation,-,15,Gateoxideintegrity,-,16,Sheetresistance(Rs_N+/P+/NW/Po),-,17,ContactResistance(Rc_N+,P+,Via),-,18,StackcontactchainCT-Viaresistancepattern:Purpose:TomonitorstackcontactRcfromCTtoV1,mainlyfocusonMET/VIAoverlay,andmetalislandprocess),RC_N+CT_V1:(1800Counts)VD=1.8V,VB=0VMeasure:ID,thenRC_N+CT_V1=(VD/ID900*RS_N+_2/100)/1800,-,19,Inlinearregion:InSaturationregion:WhenId=Idsat,Vd=VG-Vth,andSo,TransistorWATparametersandtestcondition:1.VTGm_N:VD=0.05V,VS=VB=0V,VG=0to0.8*1.8V,whereas1.8VisVDDNextrapolatetoVGatmaxslope,measureVTGm_N=VG(INTERCEPT)-0.5*VD,-,20,2.VTLIN_N:VD=0.05V,VS=VB=0V,VG=0to0.8*1.8V,whereas1.8VisVDDNMeasureVTLIN_N=VGID=0.1uA*(W/L)Tosimplifythecalculation,thetransistorwasconsideredturnedonwhenID=0.1uA*(W/L)TypicalValue:VTLIN_N_10/10=0.37VVTLIN_P_10/10=-0.44VVTLIN_N_10/0.18=0.44VVTLIN_P_10/0.18=-0.5VVTLIN_N_0.22/10=0.31VVTLIN_P_0.22/10=-0.41VVTLIN_N_0.22/0.18=0.36VVTLIN_P_0.22/0.18=-0.5VVTLIN_N3.3_10/10=0.68VVTLIN_P3.3_10/10=-0.73VVTLIN_N3.3_10/0.35=0.72VVTLIN_P3.3_10/0.35=-0.68VVTLIN_N3.3_0.22/10=0.56VVTLIN_P3.3_0.22/10=-0.68V3.VTSAT_N:VD=1.8V,VS=VB=0V,VG=0to0.8*1.8V,whereas1.8VisVDDNMeasureVTSAT_N=VGID=0.1uA*(W/L)VD=VDDN,tomakesurethatthetransistorisworkingatthesaturationstatus,-,21,4.IDSAT_N:VD=VG=VDDN=1.8V,VS=VB=0,MeasureIDSAT_N=ID(thendividebyWinsomecalculation)TypicalValue:IDSAT_N_10/0.18=6mAIDSAT_P_10/0.18=-2.59mA(600uA/um)(-259uA/um)IDSAT_N_0.22/10=4uAIDSAT_P_0.22/10=-1.1uAIDSAT_N_0.22/0.18=180uAIDSAT_P_0.22/0.18=-60AIDSAT_N3.3_10/0.35=6mAIDSAT_P3.3_10/0.35=-3mAIDSAT_N3.3_0.22/10=7.58uAIDSAT_P3.3_0.22/10=-1.61uA,-,22,5.IOFF_NVD=1.1*1.8V,VG=VS=VB=0,MeasureIOFF_N=ID(thendividebyWinsomecalculation)TypicalValue:IOFF_N_10/0.18=60pAIOFF_P_10/0.18=-30pAIOFF_N3.3_10/0.35=60pAIOFF_P3.3_10/0.35=-35pA6.BVD_NVG=VS=VB=0V,VD=1.8To3*VDDN,whereas,VDDN=1.8Vor3.3V,MeasureBVD_N=VDID=0.1uA*WTypicalValue:BVD_N_10/0.18=4VBVD_P_10/0.18=-5.21VBVD_N3.3_10/0.35=7VBVD_P3.3_10/0.35=-6.99V,-,23,7.ISUB_NVD=1.1*1.8V,VS=VB=0,VG=0.2*1.8Vto1.1*1.8V,FindISUB_N(MAX)(then,dividedbyWinsomecalculation)Monitorthehotcarriereffect,SweepVgandMeasureIb.Isub=Abs(Isub)maxIThesubstratecurrentinann-channelMOSFETresultsfromholegenerationbyimpactionizationsinducedbythechannelelectronstravelingfromsourcetodrain.Assumingimpactionizationoccursuniformlyinthepinchoffregion(nearthedrain),thesubstratecurrent,Ibs,maybewrittenasIbs=IdLwhere=ionizationcoefficientL=lengthofpinchoffregionWithVg,Ibs,andreachesamiximumvalue,thendecrease.TheinitialIbsincreaseisduetotheincreaseinIdwithVg.However,asVggoesup,thelateralfielddecreases,causingareductionin.Thus,thepeaksubstratecurrentoccurswhenthetwocompetingfactorscancelout,usuallyat0.5Vd.TypicalValue:ISUB_N_10/0.18=(1.6uA)ISUB_P_10/0.18=(-0.013uA),-,24,8.DIBL(DrainInducedBarrierLowering)VTLINVD=0.05V,VS=VB=0,VG=0to0.8*VDDNMeasureVTLIN=VGID=0.1A*(W/L)VTSATVD=1.1*VDDN,VS=VB=0,VG=0to0.8*VDDNMeasureVTSAT=VGID=0.1A*(W/L)DIBL=(VTLIN-VTSAT)/(1.1*VDDN-0.05)Thresholdvariationiscausedbytheincreasedcurrentwithincreaseddrainvoltage,astheapplieddrainvoltagecontrolstheinversionlayerchargeatthedrain,therebycompetingwiththegatevoltage.Intheweakinversionregime,thereisapotentialbarrierbetweenthesourceandthechannelregion.Theheightofthisbarrierisaresultofthebalancebetweendriftanddiffusioncurrentbetweenthesetworegions.Ifahighdrainvoltageisapplied,thebarrierheightcandecrease,leadingtoanincreasedraincurrent.Thusthedraincurrentiscontrollednotonlybygatevoltage,butalsobythedrainvoltage.,-,25,9.GAMMA_N(:bodyeffect)VD=0.05V,VS=0,VB=-1.5*1.8,VG=0to1.1*1.8MeasureVTLIN1_N=VGID=0.1uA*(W/L)thethresholdvoltagewithsubstratebias(VB)=0.443744GAMMA_N=ABS(VTLIN1_N-VTLIN_N)/ASB(VB)+2*1/2-2*1/2Since,VT=GC-QB/Cox-2B-Qox/Cox=VFB-2B+SQRT(-2B+VB)Where:VFB=GC-Qox/Coxand=SQRT(2siqNB)/CoxVTLIN1=VFB-2B+SQRT(-2B+VB)VTLIN=VFB-2B+SQRT(-2B)=(VTLIN1-VTLIN)/SQRT(-2B+VB)-SQRT(-2B)TypicalValue:GAMMA_N_10/10=0.5V1/2GAMMA_P_10/10=0.57V1/2,-,26,10.SWING_NVD=0.05V,VS=VB=0,VG=0to1.8V,MeasureVG1ID=10nA*(W/L)VG2ID=0.1nA*(W/L)SWING_N=500*(VG1-VG2)Intheweekinversion(orsub-threshold)regime,thetransistorconductsaverysmallsub-thresholdcurrent,andthedraincurrentdependsexponentiallyonthegate-sourcevoltage.Tomeasurethesub-thresholdslope,SS,whenVD=0.05V,isdefinedas:,SUBVTSLP=(slope)-1=(VG1-VG2)/log(Ileak1)log(Ileak2)=(VG1-VG2)/log(Ileak1/Ileak2)V/dec=(VG1-VG2)/log(10/0.1)V/dec=(VG1-VG2)/2V/dec=500*(VG1-VG2)mV/dec,-,27,11.Gleak_NVS=VD=VB=0,VG=-VDDN=-1.8V,MeasureIG.If50nA,considerTransistorfailthetest,skipallresttransistortests12.Gm_NMaxslopeofIDvsVGVB=013.VsubvgVD=1.1*VDDN,VB=VS=0,VG=0.2*VDDNto0.7*VDDNMeasureVGmaxISUB,-,28,-,29,-,30,Gatecapacitorkeyparameters:1)TOX,2)Leakage3)BreakdownVoltage4)Cap,WATbasicconcept/device/layout.cont,-,31,-,32,WATbasicconceptanddevice.cont,DiodeKeyParameters:CapacitorLeakageBreakdownvoltage,-,33,-,34,Testcondition:VD=-0.2V,VB=0VMeasure:ID&ComputeRs=(VD/ID)/(L/W),P+Polyresistancepattern:RSFV_PP_D15_400(OHM/SQ.)A)Purpose:TomonitorsalicideRsresistanceofP+PolyB)Design:L=400,W=0.15,WATbasicconceptanddevice.cont,SheetResistor:Rs,-,35,ContactResistance:Rc,N+AAContactresistancepattern:(RCFV_NDF_D17_3240(OHM/EA).)A)Purpose:TomonitorN+AAcontactRcDesign:Under:AAUpper:Metal-1Holesize:3240ea,C)Testcondition:VD=0.2V,VB=0VMeasure:ID&ComputeRC_N+=(VD/ID)/CountCount=numberofcontact.,WATbasicconceptanddevice.cont,-,36,WATfailanalysis&processdebugging,WATfailuremode:OutofSpec:Missingorwrongprocesssteps.OutofControl:Processfluctuation(random),Processdrift(systematictrend).Multiplegroup:Equipmentchamberoffset.WATRe-TESTandManualm