半导体物理器件复习要点

1-CheckpointListsomeelementalandcompoundsemiconductormaterials.Sketchlatticestructures:simplecubic,body-centeredcubic,face-centeredcubicandthediamondstructure.Findthevolumedensityandthe

surfacedensityofatoms.ObtaintheMillerindices(latticedirectionsandplanes).Terms:Semiconductorphysicsanddevices,Spacelattice,unitcell,primitivecell,basiccrystalstructures(fivetypes),Millerindices,volumedensity,surfacedensity,atomicbonding.StudyAssignmentsListsomeelementalandcompoundsemiconductormaterials.Sketchlatticestructures:simplecubic,body-centeredcubic,face-centeredcubicandthediamondstructure.1.11.16(1.12oftheoldedition)2-CheckpointListthepriciplesofquantummechanics.Schrodinger’swaveequation:Writethewaveequation.Whatisthephysicalmeaningofthewavefunciton?Whatistheboundaryconditions?Applicationofthewaveequation:Electroninfreespace:Derivethewavefunctionofanelectroninfreespace.Whatconclusioncouldyouobtainfromthissolution?Thequantizedenergylevelsofboundparticles.Thepenetrationdepth,thetransmissioncoefficient.StudyAssignmentsListandexplainpriciplesofquantummechanics.Schrodinger'swaveequation:Writethewaveequation.Whatisthephysicalmeaningofthewavefunciton?Whatistheboundaryconditions?Derivethewavefunctionofanelectroninfreespace.Whatconclusioncouldyouobtainfromthissolution?Derivetheenergylevels,wavefuntionandprobabilityfunctionfromtheschrodinger'swavefunctionwhenanelectronisintheinfinitepotentialwell.Terms:quantummechanics,energyquanta,wave-particleduality,theuncertaintyprinciple.Schrodinger'swaveequation,

eletronsinfreespace,theinfinitepotentialwell,thesteppotentialfunction,thepotentialbarrier.3-CheckpointDiscusstheconceptofallowedandforbiddenenergybandsinasinglecrystalbothqualitativelyandmorerigorouslyfromtheresultsofusingtheKronig-Penneymodel.Discussthesplittingofenergybandsinsilicon.Discusstheconceptofahole

intermsoftheeffectivemass,covalentbondingandenergybands.Qualitatively,intermsofenergybands,discussthedifferencebetweenmetals,insulators,andsemiconductors.Understandthedensityofstatesfunction.UnderstandthemeaningoftheFermi-DiracdistributionandtheFermienergy.StudyAssignmentsExplaintheformationofallowedandforbiddenenergybandsinasinglecrystal.Discusstheconceptofahole

intermsoftheeffectivemass,covalentbondingandenergybands.Qualitatively,intermsofenergybands,discussthedifferencebetweenmetals,insulators,andsemiconductors.Understandthedensityofstatesfunction.UnderstandthemeaningoftheFermi-DiracdistributionandtheFermienergy.Terms

Pauliexclusionprinciple,quantumstate.allowedandforbiddenenergyband.theconductionbandandthevalenceband.

hole,theeffectivemass.densityofstatesfunction,theFermi-Diracprobabilityfunction,theBoltzmannapproximation,theFermienergy.4-CheckpointDerivetheequationsforthethermalequilibriumconcentrationsofelectronsandholesintermsoftheFermienergy.Derivetheequationfortheintrinsiccarrierconcentration.StatethevalueoftheintrinsiccarrierconcentrationforsiliconatT=300K.DerivetheexpressionfortheintrinsicFermilevel.CheckpointDerivetheequationfortheextrinsiccarrierconcentration.Theproductofn0andp0.DerivetheexpressionfortheextrinsicFermilevel.Chargeneutrality---usedtodeterminetheconcentrationofelectronsandholes.PositionofEF(influencedbydopingdensityandT)StudyAssignments

1.Derivetheequationfortheextrinsiccarrierconcentration,theproductofn0andp0.2.Chargeneutrality:howtodeterminetheconcentrationofelectronsandholes?3.HowtodeterminethepositionofEF?(---influencedbydopingdensityandT)Terms:chargecarriers,effectivedensityofstatesfunction,theintrinsiccarrierconcentration,theintrinsicFermilevel.Terms:donorimpurity,acceptorimpurity,thechargeneutralitycondition,compensatedsemiconductor,degenerate,non-degenerate,positionofEF,variationofEFwithdopingconcentrationandtemperature.

5-CheckpointDiscusscarrierdriftcurrent

density.Discussthemechanismsoflatticescatteringandimpurityscattering.Definemobilityanddiscussthetemperatureandionizedimpurityconcentrationdependenceonmobility.Defineconductivityandresistivity.Discussvelocitysaturation.Discusscarrierdiffusioncurrentdensity.StatetheEinsteinrelation.DescribetheHalleffect.StudyAssignments

1.Describecarrierdriftcurrent

densityandcarrierdiffusioncurrentdensity.Defineconductivityandresistivity.What’stheEinsteinrelationship?2.Discussthemechanismsoflatticescatteringandimpurityscattering.Whatarethetemperatureandionizedimpurityconcentrationdependenceonmobility?3.Discussvelocitysaturation.Termsdriftcurrentdensity,diffusioncurrentdensity,mobility,latticescattering,ionizedimpurityscattering,velocitysaturation,conductivity,resistivity.diffucioncurrentdensity,gradedimpuritydistribution,theinducedelectricfield,theEinsteinrelation,theHalleffect.

6-CheckpointConceptofnonequilibriumexcesscarriers.Conceptofgenerationandrecombination.Whyexcessminoritycarriersaremostlyconsidered?Definetheexcesscarrierlifetime.Describetheambipolartransport.thepositionofthequasi-Fermienergylevel.StudyAssignments

1.Whataretheconceptofnonequilibriumexcesscarriers,generationandrecombination?2.Whyexcessminoritycarriersaremostlyconsidered?Definetheexcesscarrierlifetime.3.Describetheambipolartransport.4.Determineandexplainthepositionofthequasi-Fermienergylevel.

7-CheckpointExplaintheformationofthespacechargeregion.Derivetheelectricfieldandpotential

barrierofapnjunction.(themaximumelectricfieldandthebuilt-inpotentialbarrier.)Zeroappliedbias:Thebuilt-inpotential,thespacechargewidth,theelectricfield.Reverseappliedbias:thepotentialbarrier,spacechargewidth,electricfield,junctioncapacitance.Expaintheexistanceofthejunctioncapacitance.one-sidedjunctions.StudyAssignments

1.Explaintheformationofthespacechargeregion.2.Derivetheelectricfieldandpotential

barrierofapnjunction.Whatarethemaximumelectricfieldandthebuilt-inpotentialbarrier?3.Expaintheexistanceofthejunctioncapacitance.Terms:

thespacechargeregion,thebuilt-inpotential,thespacechargewidth,zeroappliedbias,reverseappliedbias,one-sidedjunction.8-CheckpointDerivetheminoritycarrierconcentrationsattheedgeofthespacechargeregiongeneratedbytheforward-biasvoltage.Drawthesteady-stateminoritycarrierconcentrationsinapnjunctionunderforwardbias.Derivetheidealcurrent-voltagerelationshipfromtheexpressionofthesteady-stateminoritycarrierconcentrationforapnjunctiondiode.DrawtheidealI-Vcharacteristicofapnjunctiondiode.Themechanismofthetotalcurrentunderforwardbias.Describegenerationandrecombinationcurrents.StudyAssignments

Derivetheminoritycarrierconcentrationsattheedgeofthespacechargeregiongeneratedbytheforward-biasvoltage.Drawthesteady-stateminoritycarrierconcentrationsinapnjunctionunderforwardbias.Derivetheidealcurrent-voltagerelationshipfromtheexpressionofthesteady-stateminoritycarrierconcentrationforapnjunctiondiode.Describegenerationandrecombinationcurrents.Terms:thepnjunctiondiode,minoritycarrierdistribution,theideal-diodeequation,thereversesaturationcurrentdensity.ashortdiode.generationandrecombinationcurrents.9-CheckpointSketchtheenergybanddiagramofzero-biased,reverse-biased,andforward-biasedSchottkybarrierdiodes.Comparetheforward-biasedcurrent-voltagecharacteristicofaSchottkybarrierdiodetothatofpnjunctiondiode.Describewhatismeantbyanohmiccontact.Drawtheenergybanddiagramofaheterojunction.Whatistwo-dimensionalelectrongas.Sketchtheenergybanddiagramofzero-biased,reverse-biased,andforward-biasedSchottkybarrierdiodes.Comparetheforward-biasedcurrent-voltagecharacteristicofaSchottkybarrierdiodetothatofpnjunctiondiode.Describewhatismeantbyanohmiccontact.DrawtheenergybanddiagramofannPornNheterojunction.Whatistwo-dimensionalelectrongas.StudyAssignments

Terms:

Schottkybarrierdiode(SBD),Schottkybarrierheight.ohomiccontact.heterojunction,homojunction.turn-onvoltage.narrow-bandgap,wide-bandgap,2-Delectrongas.10-CheckpointSketchtheenergybandsofthenpnbipolartransistorunderzerobiasandunderaforward-activemodebias.Sketchtheminoritycarrierconcentrationsthroughoutthetransistorunderthevariousoperatingmodes.Drawandexplainthecurrentdensitycomponentsinannpnbipolartransistoroperatingintheforward-activemode.DefinethephysicalmechanismofbasewidthmodulationanditseffectontheI-Vcharacteristicsofthetransistor.StudyAssignments

Terms:

bipolartransistor,base,emitter,collector.forwordactivemode,cut-off,saturation,inverseactive.currentgain,common-base,common-emi