用阶梯状掺杂埋层对超浅结进行C-V剖面分析(英文).docx

1、器件制造身成闱咐MnufacturingmdApplicationofDevicedoi：10.3969/j.issn.1003-353x.2010.01.009CVProfilingofUltrashallowJunctionsUsingaBuriedLayerwithStep-LikeDopingProfileXuCuiqin1,2,PopadicMilo§2,NanverL.K.2,RuGuoping1(1.StaleKeyl/ibofASICandSystems,DepartmentofMicroelectronics,FudanUniversity,Shanghai2004

2、33,China;2.laboratoryofECTM,DIMES,DelftUniversityofTechnology,CHDelft2600.Netherlands)Abstract：Two-sidedC-VtechniquewasinvestigatedforapplicationindopingprofilecharacterizationofSiultrashallowp*-njunctions.Expressionswerederivedfortheevaluationofthedopingprofileinthep*region,basedontheknowledgeofcap

3、acitance-voltage(C-Vr)relationshipofthep*-ndiode,thedopingprofileinnregion,andthedepletionwidthinnregionatthermalequilibrium(xM).SteppeddopingprofileinnregionwasdesignedforaccuratedeterminationofxM,acrucialparameterfortheextractionofthedopingprofileinthep*region.Medicisimulationswerecarriedoutforthe

4、C-VRrelationshipsofthep*-nandn-Schottkyjunctionswiththesamestep-likenprofile.ThedopingprofileinnregioncouldthenbeextractedfromtheC-VRrelationshipoftheSchottkydiode.Theisdeterminedwithanaccuracyof1.8nmbyacriteriondeveloped.Andthedelingprofileinthep*regioncanfinallybeextractedandshowntobeingoodagreeme

5、ntwiththeMedicisimulationresults.Keywords：two-sidedjunction;C-V;ultra-shallowjunctionsCLCnumber：TN301.07;TN3O5.3Documentcode：AArticleID：JOB-353X(2010)01-0039-01EEACC:253OB;255OB;7110用阶梯状掺杂埋层对超浅结进行C，剖面分析徐翠芹PopadicMilo*,NanverL.K.2,茹国平】（1.复旦大学微电子系专用集成电路与系统国家重点实验室，上海200433；2.代尔夫特工业大学ECTM/DIMES实验室，荷兰代尔夫

6、特2600）摘要：研究了应用双边C-V法测量超浅结（如p*-n结）的疹杂分布。推导了在已知p-n结的电容-电压（C-*）关系、n区掺杂、以及热平衡下n区耗尽层宽度（xM）的情况下计算p区疹杂浓度分布的公式。与湖是计算p区掺杂分布所需的一个关键参数，通过将n区掺杂设计成阶梯状，可实现对*的精确提取。用Medici对具有相同的阶梯状掺杂n区的p'-n和n-肖特基结进行器件仿真可得其C-Vn关系。运用常规GU法，由肖特基结的C-Vn关系可提取出n区掺杂浓度。实现了对*3的精确提取，其精度达1.8nma基于精确的为洵，运用双边C-V法提取的p*区的掺杂浓度分布与Medici仿真结果非常吻合。关

7、键词：双边结；电容-电压；超浅结中图分类号：TN3W.07；TN3O5.3文献标识码：A文章编号：1003-353X（2010）01-0039-040IntroductionUltrashallowsourceanddrain(S/D)junctionswithFoundationitem：Shanghai-AppliedMaterialsResearchDevelopmentFund(07SA06)highandabruptdopingprofilearenecessaryforgoodperformanceofMOSFETs'E.Itisveryimportantandchalle

8、ngingtomeasuretheactivateddopinglevelanditsdistributionthroughtheultrashallowjunctionsbecauseofthestringentdepthresolutionandquantitativeaccuracyrequirements.Atpresent,thereareseveralprofilingtechniques,suchassecondaryionmassspectrometry(SIMS),spreadingresistanceprofiling(SRP),differentialcapacitanc

9、e-voltage(C-V)profiling,electrochemicalcapacitance-voltage(ECV)profiling,profiling,Halleffectprofiling,andRutherfordbackscattering(RBS.Eachlechniquehasitsadvantagesanddisadvantages.Inthiswork,anoveltwo-sidedC-Vprofilingisdeveloped.ThedopingprofileononesidecanbeextractedbasedontheknowledgeoftheC-Vrel

10、ationship,thedopingprofileontheotherside,andtheboundaryofdepletionregionatthermalequilibrium(.Thetwo-sidedprofilingtechniquecanbesuccessfullyappliedfortheprofilingofp+regionofp*-njunctionwithasteppedndopingprofile.1 TheoryofTwo-SidedCVProfilingTechniqueThedopingprofileofanarbitrarydopedp-njunctionis

11、showninFig.1./Vd(x)andN.(x)representthedonorprofileinnregion(x<0)andacceptorproGleinpregion(x>0),respectively.W(VT)isthewidthofthedepletionregionwhenthetotalpotentialdropthroughthejunctionequalstoVytwhichisthesumofthebuild-involtage,andreversebiasVr.xnandxparethecoordinatesofthedepletionregion

12、edgesinthevicinityofneutralnandpregions,respectively.Fig.1DeGnitionsofanarbitrarydopedpnjunction图1任意掺杂pn结的定义Assumingthatalldopantatomsareactive,withdepletionapproximation,theequationscanbeobtained一习:electricallyfollowing收(4)%"=一L业与g1-秋(*)宓住QAtthermalequilibrium,equalsto*，andxnequalstoxM.FromEq.

13、(1),thefollowingequationcanbeobtainedWithacertainreversebiasvoltageapplied.Eq.(1) canbewrittenas；住山一滁+'斋(5)CombiningEqs.(4)and(5)yieldsQbi="eJo败(Vr)=-:CUr)Mr(6)WhereAistheareaofthediode,tisthepermittivityofthesemiconductor,andCisthecapacitanceofthediode.Witharightassumptionofxoandtheknowled

14、geofthedopingprofileinnregion,usingEq.(6),xnti(Ur)whichstandsfortheestimatedrelationshipbetweenxnandVrcanbecalculated.ThenbasedonthemeasuredC-Vrrelationshipofp-njunction,W()canbecalculatedandtheestimatedxp-relationship,xpM(i(Yr)canbecalculatedusingEq.(2).Intheend,N.(xp)canbereconstructedfromEq.(3).2

15、 MediciSimulationofTwo-SideC-VProfilingInthetwo-sidedC-Vprofiling,isanimportantbutunknownparameter.What'smore,thedopingprofileinnregioncannotbetakenasknowndirectly.Inthiswork,itissuggestedthatifusingap*-njunctionwithastep-likenprofile,thevalueofcanbeevaluatedaccurately.Andthedopingprofileinnregi

16、oncanbemeasuredonn-Schottkydiodewiththesamenprofileasp*-njunction.MedicisimulationsareimplementedfortheC-VRrelationshipsofp*-nandSchottkydiodeswiththesamestep-likedopingprofileinnregion.Atthermalequilibrium,thesimulateddopingandcarrierprofilesofp*-njunctionwithstep-likenprofileareshowninFig.2.Theare

17、asofthep*-ndiodeandSchottkydiodearebothsetto1mx1pm.DCsolutionsofSchottkyandp*-ndiodearesolvedatdifferentreversebiases,0-25Vand015Vwithastepof0.1V,respectively.Duringthisprocess,Poisson*sequation,continuityequationsandthecarriertransportequationsareallcoupledandsolvedbyusingnumericalmethod.Mediciperf

18、ormsACanalysisasapost-processingstepaftereachDCsolution.ACsmallsignalsimulationsarecarriedoutateachDCbiasingbyapplyingasinufu)idalsignalutafrequencyof1MHzwithasmallamplitudeof10mV.ThesimulatedC-VKcharacteristicsofthep*-ndiodeandn-SchottkydiodewiththedopingprofilesareshownintheinsetofFig.2.Fig.2Simul

19、atedcarrieranddopantconcentrationprofilesofp*-njunctionatthermalequilibrium,theinsetshowsthesimulatedC-VHcharacteristicsofthep*-nandn-Schottkydiodes图2仿真中的p-n结掺杂浓度分布以及热平衡F的城流子浓度分布，插图为仿真得到的p-n结和n肖特基结的C-*关系Takingtheestimatedelectronprofileofn-Schottkydiodeastheelectronprofileatthermalequilibriumofthep*

20、-ndiode,basedontheMedicisimulatedCVKrelationshipofp*-njunction,two-sidedprofilingtechniqueisimplementedwithdifferentassumptionofasiwinw.=-99-96nm).Withdifferent,Mumc,differentxpzi-VrrelationshipscanbecalculatedassliowninFig.3.Theoretically,thedepletionwidthinpregionshouldincreaseasthereversebiasincr

21、eases.However,-Kt/VFig.3Estimatedxp-VKrelationshipsfordifferentxM,uiwe图3不同gi下所估算出的x-VH关索asshowninFig.3,withla建eraume,theestimatedxp-VKrelationshipsdecreaseatthefirstfewbiaspoints.Thisabnormalphenomenoncanbeexplainedasfollows.AsindicatedinFig.2,theestimatedelectronconcentrationdecreasesasxincreases.F

22、orthesameamountofelectronstobedepleted,ifx*8umrislargerthantherealvalueof为thestepofxn)willbelargerthantherealvalue.IfaMumcistoolarge,thestepofxnMti(Vr)maybeevenlargerthanthestepofW(Yr),whichinducesxpeslj(FR)todecreaseatthefirstfewbiaspointsuntilxnreachesthehighlydopedregion.Thisphenomenonisillustrat

23、edmoreclearlyinFig.4.With丸sazEeequals-96nm,forthefirstfewbiaspoints,thestepwidthofxn_cMi(Hr)islargerthanthatofW(Vr),sothestepofxp5(*)isnegative,andxpe8ti(Hr)woulddecreaseatthefirstfewbiaspoints.Afterafewbiassteps,theconcentrationdifferenceinducedbythelargerxMassumcwilldisappearandthestepofxpwli(VR)b

24、ecomepositiveandxpc#li(Vr)willincrease'*.ThisphenomenonoffersawaytodeterminetheupperlimitofInthiscase,thelimitisthattheassumedshouldbesmallerthan-97.2nmasindicatedinFig.3.If心.umeissmallerthantherealvalueof«thestepofxncgli(Vr)willbesmallerthantherealvalue,sothestepofxpMli()willalwaysbepositi

25、veandxpeMi(VR)willalwaysincreasewithVr.Thereforeitisdifficulttofigureoutthelowerlimitoffromthexprelationship.Ontheotherhand,thewrongaMMinw.willresultinnotonlywrong%pwlibutalsowrongNaIf*洵皿叩职issmallerthantherealvalueofxp_mi(Ur)seemsFig.4Withxz=-96.0nm,thestepsofdepletionwidth,theestimatedxn,andtheesti

26、matedxpasfunctionsofreversebias图4七45=-96.0nm时.耗尽层宽度、估算出的%、和与反偏电斥的关系normal,buttheestimatedp+dopingprofile,asshowninFig.5,isnotsmooth'】.ThisphenomenoncanbeusedasacriteriontodeterminethelowerlimitofwhichisspecifiedasxMmin.AsshowninHg.5,whendecreasesto-99nm,theeg|j-xbecomesnon-smooth,Fig.5Estimatedp

27、*dopingprofilewithxMaMluin<.=-98.0,99.0and-100.0nm图5xs.ze为-98.0,-99.0,-100.0nm时所提取的P区掺杂浓度分布InFig.6istheacceporprofileestimatedwith=-98nm,andthesimulatedacceptorprofileandholeprofileatthermalequilibrium.Fig.5Estimatedp*dopingprofilewithxMaMluin<.=-98.0,99.0and-100.0nm图5xs.ze为-98.0,-99.0,-100.0n

28、m时所提取的P区掺杂浓度分布InFig.6istheacceporprofileestimatedwith=-98nm,andthesimulatedacceptorprofileandholeprofileatthermalequilibrium.rm。/*,NAlthoughitisimpossibletohavetheexactvalueofrealinpractice,Netli(x)shouldbeveryclosetothetruevalueswhentheinterval(xMmin,)issmallenough,around1.8nminthiscase.Astheexperi

29、mentalapplicationofthetwo-sidedC-VproGlingtechniqueisconcerned,accuratemeasurementofjunctionareaisnecessary.Otherwise,thedopingprofileinnregionandconsequentlythedopingprofileinthep*regioncannotbesuccessfullyestimated.Fig.6Acceptorprofileestimatedwithx”=-98.0nm,aridthesimulatedacceptorprofileandholep

30、rofileatthermalequilibrium图6xo=-98.0nm时所提取的受主搂杂浓度分布，及仿真所得到的热平衡下的受主和空穴浓度分布Fig.6Acceptorprofileestimatedwithx”=-98.0nm,aridthesimulatedacceptorprofileandholeprofileatthermalequilibrium图6xo=-98.0nm时所提取的受主搂杂浓度分布，及仿真所得到的热平衡下的受主和空穴浓度分布?£>MWConclusionThenoveltwo-sidedC-VproGlingtechniqueisproposedt

31、hatthedopingprofileononesideofp-ndiodecanbecalculatedbasedontheknowledgeoftheC-*relationship,thedopingprofileontheotherside,andtheboundaryofdepletionregionatthermalequilibrium.Hietwo-sidedC-VprofilingtechniqueissuccessfullyappliedforSiultrashallowjunctions.Theteststructureofp*-nandn-Schottkydiodeswi

32、ththesamestep-likenprofileisdesignedforextractionofthedopingprofileinthep*regionusingthetwo-sidedprofilingtechnique.BasedontheMedicisimulationoftheC-relationshipsofultra-shallowp*-nandn-Schottky,ononehand,thedopingprofileonthensidecanbeextractedfromtheC-VRrelationshipofSchottkydiode.Ontheotherhand,w

33、ithdifferentaume»applyingthetwo-sidedC-Vprofilingtechnique,theupperandlowerlimitsofcanbedetermined,baseonthe气。"*andVRrelationships,respectively.Theaccuracyofisshowntobeabout1.8nm.Itisdemonstratedthatifisassumedtobewithintheupperandlowerlimits,thedopingprofilesinthep*regioncanbeaccuratelyev

34、aluated.Thereforeitcanbeconcludedthatthenoveltwo-sidedC-Vprofilingtechniquemaybeappliedfortheextractionofthedopingprofileofultra-shallowjunctions.(下转第89页)了大量的键合过程中换能杆末端轴向的速度信号。通过分析这些键合的强度得到了欠键合和过键合对应的功率设置范围。分析了超声功率设置和键合温度对换能杆振幅的影响规律，解释了不同功率设置和温度导致欠键合和过键合的可能原因，建立了功率设置和温度对换能杆振幅影响的模型。参考文献：】WANGFL,UJH,H

35、ANL,etal.EffectofultrasonicpoweronwedgebondingstrengthandinterfacemicrostructureJ.TransactionsofNonferrousMetalsSocietyofChina(EnglishEdition),2007,17(3)：606-611.2 SUCT,CHIANGTL.Optimaldesignforaballgridarraywirebondingprocessusinganeuro-geneticapproachj.IEEETransonElectronicsPackagingManufacturing,

36、2002,25(1)：13-18.3 IQNGZL,HANL,WUYX,etal.ExperimentstudyoftemperatureparametereffectonbondingprocessandqualityinthermosonicwirebondingC/Procof6,hIntConfonElectronicsPackagingTechnology.2005,Shenzhen,Guangdong,China,186-193.4 许文虎，韩缶.Hilbert变换在求取超声换能系统速度导纳中的应用J.现代机械.2005,(6):6-15.5】帏雷，许文虎，李涵雄.超声键合换能系统

37、非稳态特性实(上接第42页)References:1 WONGHSP,FRANKDJ,SOLOMONPM,etal.NanoscaleCMOSJ.ProcIEEE,1999,87:537-570.2 MOOREGE.ProgressindigitalintegratedelectronicsC/7ProcofIEDM.Washington,USA,1975:11-13.3 KURATAH,SUGIIT.Impactofshallowsource/drainontheshort-channelcharacteristicsofpMOSFETsJ.IEEEEDL,1999,20(2):95-96.

38、4 JONESEC,ISHIDAE.ShallowjunctiondopingtechnologiesforULSIJ.MaterSciEng,1998,24：1-80.5 SCHRODERDK.SemiconductormaterialanddevicecharactenzationM.NewYork：JohnWileyandSons,1998：160-272.6 MANHJJD.OnthecalculationofdopingprofilefromC(V)measurementontwo-sidedjunctionsj.IEEETransonED,1970,17(12):1087-1088.7 Synopsysinc.Taurusmedici:m