迁移率散射机理

工作汇报——迁移率散射机理ThicknessofBOXandGroundPlaneComparedFDSOIdeviceswithdifferentBOXthicknesseswithorwithoutgroundplane(GP)ThicknessofBOXandGroundPlaneDrainInducedBarrierLowering(DIBL)wasreducedbyaround50mVbyusingathinBOXinsteadofathickBOX,GPprovidesananditionalDIBLreduction.ThicknessofBOXandGroundPlaneThesubthresholdslopeisslightlydegradedbyusingthinBOXdueintothecapacitanceincreaseinducedandalsotothesuppressionofthedepletedzoneunderBOXintthecasewhereGPisused.ThicknessofBOXandGroundPlaneThemobilityreductionascomparedtotheuniversalmobilitycurvesisduetothereducedthicknessofthefilm(~8nm)andalsototheHigh-Kdielectric.ThicknessofBOXandGroundPlaneId(Vg)characteristicsQuantumModelingoftheCarrierMobilityinFDSOIDevicesComputedtheelecctronandholemobilitiesinultrathinbodyandburiedoxide,fullydepletedsilicononinsulatordeviceswithvarioushigh-kmetalgate-stacksusingnonequilibriumGreen'sfunctions(NEFG).ThemobilityinUTBB-FDSOIdevicesisactuallylimitedbyacomplexinterplaybetweencarrier–phononsinteractions,frontinterfaceroughness(FSR)andbackinterfaceroughness(BSR),remoteCoulombscattering(RCS),andpossiblyremotephononscattering(RPS).Thestrengthofmostofthesemechanismsdependsalotontheappliedfrontandbackgatebiasvoltages.TheseresultsshowthatFDSOIdevicesareaforemosttooltosortoutthedifferentscatteringmechanismsinSidevices,andthatNEGFcanprovidevaluableinputstotechnologycomputeraideddesign.developedamultibandsk·pnonequilibriumGreen’sfunctions(NEGF)codeabletodealwithrealistic,largescalestructuresQuantumModelingoftheCarrierMobilityinFDSOIDevices7.5-nm-thickSifilmona25-nmBOX;Thefrontgate-stackismadeofa1.8-nm-thickHfSiONlayerontopofaSiONinterfaciallayer(IL)withthiccknessrangingfrom1.2to4nm.Theelectronandholemobilitishavebeenmeasuredalong[001]withasplitCVmethod.ThecarriermobilitiesshowastrongdependenceonVbgasthedeviceswitchesfromfronttobackinterfaceinversion.theelectronandholemobilitypeakshiftsfromlow-carrierdensityforVbg=0V,tohigh-carrierdensityn≈1013cm−2forVbg=±8V.ILtQuantumModelingoftheCarrierMobilityinFDSOIDevicesNEGFmethodology:Theelectronbandstructureisdescribedwithanonparabolictwobandsk·pmodelcouplingoppositeΔvalleys;andtheholebandstructurewithathreebandsk·pmodel.InSilongitudinalmasstransversemassInSiO2isotropicmassbarrierattheinterface0*916.0mml0*191.0mmt0*5.0mmeVV5.4QuantumModelingoftheCarrierMobilityinFDSOIDevicesNEGFholedensityinthedeviceatbackgatevoltageVbg=−8V,forsheetdensitynincreasingfrom(a)to(c)(tIL=1.2nm).QuantumModelingoftheCarrierMobilityinFDSOIDevicesBreakdownoftheelectronmobilityinPH,FSR,BSR,andRCScomponents,atbackgatevoltages(a)Vbg=0Vand(b)Vbg=8V.theRCScomponentisplottedfordifferentILs.Thetotalmobility(MATT)ofthetIL=1.2-nmdevicehasbeencomputedwithMatthiessen’srule.QuantumModelingoftheCarrierMobilityinFDSOIDevicesRoom-temperature(a)electronand(b)holemobilityasafunctionoftIL,attwocarrierdensitiesn=2×1012cm−2andn=1×1013cm−2.ThesolidlinesaretheNEGFcalculations,thedottedlinestheexperimentaldata.RometeCoulambScatteringLimitedMobilityMonteCarlosimulationofremote-Coulomb-scattering-limitedmobility.TheleftpictureshowselectronmobilitycurvesvsthetransverseeffectivefieldfordifferentvaluesofoxidethicknesstakingintoaccounttheeffectsoftheRCS,Phonon,surfaceroughness,andCoulombscatteringaretakenintoaccount.TherightpictureshowsdependenceoftheRCS-limitedmobilityonoxidethicknessRometeCoulambScatteringLimitedMobilityscatteringmechanismandmatrixelementsCarrier-PhononScatteringMechanismacousticphononscatteringCarrier-PhononScatteringMechanismopticalphononsaccountingforboththef-andg-typeprocesses.Inthisworktheunscreenedsccatteringmatrixelementsateitherthefrontorback-interfacceswereas(4),whereZintisthepositionoftheinterface.Carrier-PhononScatteringMechanismexperimentaldataandsimulationresultsCarrier-PhononScatteringMechanismAffectionofdifferentTsiDespitetheμeffofthefirstprimedsubbanddecreasesforTsibelow15nm,theaverageμeffdoesnotreducedowntoapproximately3.5nm,becauseelectronscontextuallymovetothefirstunprimed,highermobilitysubband.Carrier-PhononScatteringMechanismSurfaceOpticalScatteringSurfaceRoughnessScatteringGateinterfaceSurfaceRoughnessScatteringBuridInterfacePerturbationHamiltonianduetothedisplacementoftheburiedinterfacefromtheplanez=Twatagivenpositionr0oftheburiedinterfaceinasinglegatesilicononinsulatorinversionlayer.SurfaceRoughnessScatteringElectronmobilitycurvesfordifferentvaluesofthesurfaceroughnessparametersforasinglegatesilicon-on-insulatorinversionlayer.SurfaceRoughnessScatteringidealinterfacesvsroughinterfaces