汉语会话301句：第十一课.我要买橘子

WAT-电性参数介绍(WAT-Parameters-introduction)FlowWhyWAT?WATParameterReview.ProcesstestMethodology.DevicetestMethodology.ProcessFactorInfluenceonWATPara.WATApplicationGeneralGuide-linewhenWATfailExampleintroduceWhyWAT?DebugtheProcessError.MonitorProcessWindow.CheckDesignRule.ControltheProcessParameters(SPC).ReliabilityCharacterization.DeviceModelingforCircuitDesign.DevelopnextGeneration.TestsiteandTestlinelocationDeviceCategorizationActiveDeviceMOSFET(N/P),FieldTransistor,BJT,DiodePassiveDeviceResistor,CapacitorsDesignrulesIsolation,lines(Spacing,Continuity)contact,extensionResistorDiffusionregionsN+,N-,P+,N-Well,P-Well,Deep-NWThinfilmsP1,P2,M1,M2,M3Contact:C3toN+/P+,ViaC3toP1,P2WATParameterReviewProcessPart:Spacing(Bridge,short)Continuity(Open)IsolationSheetRsContactRcKelvinStructureforResistanceIntegrity(Interlayerdielectric)ExtensionrulecheckCDmeasurementJunctionleakageDevicePart:Gm(Vth,CurrentGain)Idsat(Asym)IoffSwingGammafactorBKVIsubLeff,Rext,WeffFieldDevicetestCapacitanceProcessPart:(1)Spacing(Bridge,short)Define：验证在Process中，同层/同层之间的隔绝能力!Measurementmethod：Force1uA电流到导线上，假若线路中有short，则测量出的电压值就偏低(<7volt.需注意此Structure之bottomlayer可垫其它layers,以模拟不同topography下Photo.&Etching的能力！Pad1Pad2Spacing:(P1,P2,M1,M2,M3)Width:(P1,P2,M1,M2,M3)ProcessPart:(2)Continuity(Open)Continuity的值可反映出Metal,Poly1orPoly2CD的控制能力！一般来说，此项参数要与Spacing要同时来看，如此才能判定Layer的status是否正常！Pad1Pad2Spacing:(P1,P2,M1,M2,M3)Width:(P1,P2,M1,M2,M3)ProcessPart:(3)IsolationDefine：验证在Process中，两不同层之间的隔绝能力！PS：此Pattern要注意,若oxidationquality太差,亦会影响到P1/C3是否short的误判Isolationexample：P1/C3,P2/C3,P1/P2,M1/M2…PAAC3M1Poly1PAA外框P+IM,P-IMNW外框PFIMProcessPart:(4)Sheet（薄层电阻Rs）Define：因厚度测量不易，故Define之σ=1/ρ=nqμR=V/I=ρ(L/WT)=(ρ/T)x(L/W)Rs=ρ/T=Rx(W/L)PS：σ(Conductivity传导系数)；ρ(Resistivity电阻率)；μ(mobility迁移率)；n(concentration浓度)；T(thickness厚度)；NAAPWC3NAAM1C3M1Poly2N+IMPN-IMPPWPoly1ProcessPart:(5)Contact（接触电阻）RcDefine：利用Chain的结构,将contact的阻值以Patterndesign的方式模拟出实际的contactRc大小！PS：(1)RcNormalize后的大小，往往会失真，故当个数过多时，不建议Normalize！(2)以patterndesign而言,有垫其它layer（如右下)的Structure在CMP的process中已失去参考价值了！M2M2M1ViaM2M20.4651.251.15M2P1P2M2ProcessPart:(6)KelvinStructureforResistanceDefine：以ForceCurrentthenSenseVoltagedrop的方式,测量低阻值的导线或Contact的四端电阻测量法！PS：一般来说在Req>50的结构中,ForceI=0.01uAandVoltagelim=10V!(Req=L/W)Pad1Pad2Pad3Pad41um15um70um2um(W)70um1000LProcessPart:(7)Integrity(Gate-Oxide-Integrity)Define:验证Gateoxide的Quality好坏之一项参数当Gateoxideuniformity不均,或Interface间有defects时,会形成一漏电流路径失去OxideIsolation的能力！Measurementmethod:一般测量法不外乎ForceV/IandmeasureI/V1.ForceVandmeasureI:SweepVoltonPolygate,andVb=groundthenmeasureIg(about~pA),IfIgincreaseto1uA,thisSweepVoltisBKV(normallarge7V)2.ForceIandmeasureV:Force1uAonPolygatethenmeasureVoltagePS:测量方式取决于Patterndesign(commonpadissue)WELLPolyGateProcessPart:(8)ExtensionrulecheckDefine：以sense漏电流的方式，测量Contactoverlay的Designrulecheck!PS：(1)一般来说，layout的结构会采用十字架的形式，最大的好处是在把shotissues的问题抓出!!(2)miss-align与contactnumber无关！M2ViaM1M1exttovia用Poly4垫ProcessPart:(9)CDmeasurementDefine:籍由测量两条同长度，不同宽度的电阻，换算出其宽度CD大小！PS:当W=W1时可测量得电阻R1W=W2时可测量得电阻R2R1=Rs*L/(W1-ΔW)R2=Rs*L/(W2-ΔW)R1/R2=(W2-ΔW)/(W1-ΔW)则ΔW(CDloss),Rs皆可求得！(P1CD大小影响到Channellength的长短,需特别注意）ProcessPart:(10)JunctionleakageDefine：一般来说leakage指的是反向偏压时的漏电流测量，通常有以下三种分类：1.Contactleak2.Dielectricleak(usuallyforDRAM)3.Junctionleak(bulkorperi)PS:I-bulk(meas)=A-bulk*J-area(current/um2)+L-peri*J-peri(current/um)I-finger(meas)=A-fing*J-area(current/um2)+L-peri(current/um)(J-area,J-peri可求）PW拉出NAA有打BlanketN+impN-impC3M1DevicePart:Gm(Vth,CurrentGain)Define:Gm=(ΔId/ΔVg)Linear:Id=1/2(μCoxW/L)(2(Vgs-Vt)Vds-Vds2)Gm=μCoxW/LμSaturation:Id=1/2(μCoxW/L)(Vgs-Vt)2Gm=μCoxW/L(Vgs-Vt)Pinch-Off:Vds=Vgs-VtGm=μCox(W/L)Vdsβ=μCox(W/L)PS:Ifβvalueabnormal,ItmayhaveGox,Lefforimplantissues.VthMeasuremethod:Step1:Vds=0.1Vs=Vb=0andswoopVgStep2:PlotIdsVgsandGmVgscurvesStep3:findGm(max),plotslopofthispointonIdsVgsFromLinearfunctionsetId=0thenVth=Vgs-V03VgIdDevicePart:Idsat(Asym)Define:Idsat=IdsatVgs=Vds=VccIdsMeasuremethod:Step1:Vs=Vb=0,Vd=VccandSweepVgStep2:PlotIdsVgsStep3:FindIdsatVg=Vd=VccIdsAsymmetrycheck:Step1:FollowingtheIdsmeasurement.Step2:ChangeDrainandSourcePin-assign,thenmeasureIds’.Step3:Asym=ABS(Ids-Ids’)/IdsPS:IfIdsAsymmetryAvnormal,ItmayhavetheIsub,(orPolygatenon-overlapissues)orLDDN-Rs,orContactRcsomethingstrouble!ASMU2VgGDSSubVsubSMU3IdVdSMU1DevicePart:IoffDefine:Ids=IoffatVgs=Vs=Vb=0,Vds=VccIoffMeasuremethod(Directmeas.):Step1:Vs=Vb=0,Vd=VccandSweepVgStep2:PlotIdsVgsStop3:FindIdsatVg=0Ps:测量机台的灵敏度，须注意与曲线的相关联性！IoffMeasuremethod(外插法):Step1:FollowtheIoffDirectmeas.methodStep2:PlotMaxslopofthiscurveonlog(Ids)VgsStep3:FindtheIdsatVg=0intercept.logIdVgVd=VcclogIdVgVd=VccDevicePart:Swing(SubthresholdSlop,St)Define:Swing=(Δlog(Ids)/ΔVgs)-1=2(kt/q)(1+Cd/Cox)**当Vg逐渐增加,channelaccumulation>deplation>weakinversion>stronginversion,Swing既是测量weakinversion时Id与Vg的变化程度!!(exponential)DIBleffectmeasurement:Step1:Vs=Vb=,Vd=andSweepVgStep2:Plotlog(Ids)VgsStep3:PlotMaxslopofthiscurveonlog(Ids)VgsStep4:Repeat(a)butVd=VccStep5:Repeat(b),©PS:如果发生punch-through(Subsurface-DIBL),HighdrainStwilllargerthanLowdrain.(Swing越大,Leakage越大)01VDS=5VVDS=0.1VVGIDDevicePart:GammafactorDefine:γ=(2εqNa1/2/Cox=ΔVt/((2Φf+Vbs1)1/2-(2Φf+Vbs2)1/2)Vt=Vf+2Φf+(2εqNb(2Φf+Vsb))1/2/Cox**Gammafactor是在计算Substrate与Source间非等电位时，对Vt变化的影响.(Vt值需依Vbs的大小改变来计算)Measurementmethod:Step1:FixedVd=VStep2:MeasureVtundervariousSubstatebias.Step3:PlotVtversus((2Φf+Vbs)1/2curveStep4:slopeofthecurveistakentobeGammarfactor.PS:Vtadjusment,Deepimplant,wellimplant,wellimplant都会影响此一参数，通常Vt浓度越高，γ值越大!同理，不同的device在相同的Back-bias测量下，ΔVt差值，亦代表着γ值的影响VDVGN2N1DevicePart:BKVDefine:Drainvoltagewhichproduces1uADrainCurrent.BreakdownVoltage是用来testMOS的耐压程度。(1)在Longchannel的Device，看的是S/Dtowell间junction的崩溃电压(2)在Shortchannel的status，看到的BKV，有可能是来自draintosource因punch-through造成的低电压现象!PS:可籍由Id流到IsorIb来判断BKV由何种造成！Measurementmethod:Step1:Vs=Vg=Vb=VStep2:setupDraincurrentlimitedat1uA.Step3:PlotIdsVdsStep4:SweepVdandfindtheVoltageatId=1uAN+N+VSVGVDVBDevicePart:IsubDefine:Isub(MeasureMOShotcarriereffect.)Isub=f(Vds,Vgs)(1)Vds对Isubimpact:PinchoffpointVDsat=Vgs–VtIfVds,VD-VdsatthenEmax,α,Isub(2)Vgs对Isubimpact:一开始Vgs,IdthenIsub,但当过pinchoffpoint时Vgs,VD-Vdsat,thenEmaxIsubMeasurementmethod:Step1:Vs=Vb=0V,andVd=VccStep2:SweepVg(Vgmin>1/2Vd)Step3:PlotIsubVgsStep4:Isub=IsubmaxPS:IfIsubabnormal,itmaycausefromhotcarrier,Polygatenon-overlap,Contactoveretching…andsoon.AVgGDSSubIsubSMU3IdVdSMU2SMU1AVsubMeasurementCircuit0Method,CharacteristicsIsubVgPeakPointVglimit=VdDevicePart:Leff,WeffandRextDefine:Leff=Lmask-2ΔL,Rext=Rm-Rchannel,Weff=Wmask-2ΔW公式推导：IDS=(Weff/Leff)*Cox*μn*(Vgs-Vt-0.5VDS)VDSRch=VDS/IDS=Leff/(Weff*Cox*μn*(Vgs-Vt-0.5VDS))Rm=Vf/Im=Rext+Rch=Rext+A(Lmask-2ΔL)A=1/(Weff*Cox*μn*(Vgs-Vt-0.5VDS))Measurementmethod:Step1:FixedVDS=0.1V,Vb=Vs=0VStep2:变化Vgs-Vt=2,3VStep3:PlotRmLmaskStep4:选相同的ChannelWidth不同的length的device测量不同的Vgs-VtBias下的IDS,计算Rm=VDS/IDSStep5:计算两直线交点X轴截距=2ΔL(2ΔW算法同）Y轴截距=Rext01432567Rext=1650100150200VDS=0.1VVgS=0VGS=6VVGS=8VVGS=10VVGS=12VVGS=14VDevicePart:FieldDevicetestDefine:测量Activeregion与fieldoxide所形成的寄生元件之Isolation能力测试！考虑不同的layout结构，有以下两种测量法：Measurementmethod:FieldOxide上有导电材料覆盖：此结构如同一AMOS元件，MOSVt的大小，即反映出FieldIsolation能力的好坏！PS:测量方法同Vth测量法！(2)Fieldoxide上无导电材料覆盖：此结构考虑Acitverange间implant浓度的Isolation能力，一般是测量Constantcurrent(1uA)下的耐压度PolyAAFOXDevicePart:Capacitance(thicknessmeas)Define:电容的结构常见的有一般介质电容与MOS电容两大类，差别在参考极板的组成成分！Measurementmethod:(HP4284)(1)For一般介质电容：ForceVoltage的极性与电容大小无关！(2)forMOS电容：Gox电容的测量方面，要避免空乏层电容的形成，才能算出ThicknessPolyonPW:加负压于Polygate上,PW接地！PolyonNW:加正压于Polygate上,NW接地！ProcessFactorinfluenceonWATParaThresholdVoltage(Vt=VFB+/-(2ΦF+QBO/COX)QBO=(2εqNB(2ΦF+VSB))1/2(1)NB(WellandSubCon.),QBO,Vt(2)GateOxide(a)Thickness:tox,COX,Vt(b)Quality:Qfc,Vt(VFB=Φms-Qfc/COX)(3)Vtadjust(Vtimp,deep-imp.)(4)Poly1CD(Leff),QBO,Vt(forshortchannel)(5)S/Dimplant,Vt(Forshortchannel)ProcessFactorinfluenceonWATParaGainfactor:β=μCOX(W/L)Mobilityμ,Ida)GOX/Siinterfacequality,mobility,currentGainb)CannelimplantDose,mobility,currentGainP1CD,L,currentGainGOXthickness,COX,currentGainGAMMAFACTORNB,COX(GOXthickness较厚),γγ=（2εqNB)1/2/COX=ΔVt/((2Φf+Vbs1)1/2-(2Φf+Vbs2)1/2)ProcessFactorinfluenceonWATParaSaturationCurrent:Id=1/2(μCOXW/L)(Vgs-Vt)2Vtimplant,IsatGOXthickness,COX,IsatEffectivechannellengthLeff,Isata)Poly1CD(defineLeff),Isatb)S/Dimplantc)ThermalBudget,Isat(LateralDiffusion)Weff,Isata)NitrideCD,Weff,Isatb)Bird’sbeakencorach,IsatProcessErrorDebuggingWATRe-TESTandBenchMeasSearchedonthePromisTrack-in,track-outtimingcheck.(Issuestage)Holdreasoncheck.Processflowcheck.EquipmentalarmcheckandSorting.In-linecheck.(ViewChart…andsoon)STRlotSEMandTEMcheckExampleintroduceCase1:P1/P2Cap.Fail(lower)Case2:P+RsFail(higher)Case3:NMOSIdsatFail(lower)Case4:PMOSIdsatFail(lower)Case5:N/PMOSIsatallFail(lower)simpleμσγΔαβΦερ