ArF准分子激光诱导4H-SiC表面缺陷态调控电接触性能研究

ArF准分子激光诱导4H-SiC表面缺陷态调控电接触性能研究ArF准分子激光诱导4H-SiC表面缺陷态调控电接触性能研究

摘要：本研究基于ArF准分子激光诱导技术，探究了4H-SiC表面缺陷态对电接触性能的影响以及如何通过调制缺陷态实现电接触性能的改善。通过刻蚀技术和扫描电镜等分析方法，分析得出ArF准分子激光对4H-SiC表面缺陷态诱导的能力。通过比对样品模拟实验和理论模拟实验的结果，得出了激光功率、脉宽和频率对表面缺陷密度的影响规律。通过电学测试验证在不同的激光参数下所产生的缺陷态变化对电接触性能的影响，发现在一定条件下，缺陷态密度的控制能够达到电接触性能的优化。本研究对于探究ArF准分子激光诱导技术与表面缺陷态之间的关系具有重要意义，同时对SiC材料的应用有很大的推动作用。

关键词：ArF准分子激光、4H-SiC表面缺陷态、电接触性能、缺陷态控制、电学测试

Abstract:ThisresearchisbasedonArFexcimerlaserinducedtechnologytoexploretheeffectsofsurfacedefectstatesontheelectricalcontactpropertiesof4H-SiCandhowtoimprovetheelectricalcontactpropertiesbymodulatingdefectstates.Throughetchingtechnologyandscanningelectronmicroscopyandotheranalysismethods,itwasfoundthatArFexcimerlaserhastheabilitytoinducesurfacedefectstatesin4H-SiC.Bycomparingtheresultsofsamplesimulationexperimentsandtheoreticalsimulationexperiments,theinfluenceoflaserpower,pulsewidthandfrequencyonsurfacedefectdensitywasrevealed.Throughelectricaltests,itwasverifiedthatchangesindefectstatesproducedunderdifferentlaserparametershaveanimpactontheelectricalcontactproperties.Undercertainconditions,controlofdefectdensitycanimprovetheelectricalcontactproperties.ThisresearchhasgreatsignificanceforexploringtherelationshipbetweenArFexcimerlaserinducedtechnologyandsurfacedefectstates,anditalsohasagreatpromotioneffectontheapplicationofSiCmaterials.

Keywords:ArFexcimerlaser,surfacedefectstatesof4H-SiC,electricalcontactproperties,defectstatecontrol,electricaltests。TheArFexcimerlasertreatmentcansignificantlyincreasethesurfaceenergyof4H-SiC,whichisattributedtothemodificationofsurfacedefectstatesinducedbythelaserirradiation.Thesurfacedefectstatesplayacrucialroleindeterminingtheelectricalcontactpropertiesof4H-SiC.TheelectricaltestsrevealthattheArFexcimerlasertreated4H-SiCexhibitsasignificantimprovementintheelectricalcontactpropertiescomparedtotheuntreatedones.ThisimprovementcanbeattributedtothereductionofthedefectdensityattheSiCsurfaceandtheenhancementofcarriertransport.

Furthermore,themechanismofsurfacedefectstatemodificationbyArFexcimerlaserirradiationhasbeeninvestigated.Itisfoundthatthelasertreatmentcansignificantlyreducethedensityofsurfacestatesandalsopassivatesomedeepleveldefects.ThereductionofsurfacestatedensitycanbeexplainedbythefactthatthelasertreatmentcanremovesomecarbonclustersontheSiCsurface,whichareresponsiblefortheformationofsurfacestates.Inaddition,thelasertreatmentcanalsopassivatesomedeepleveldefectsbyintroducingadditionalcarbonatomsintotheSiCcrystallattice,whichcaneffectivelyreducethedensityofdeepleveldefectsattheSiCsurface.

Inconclusion,ArFexcimerlasertreatmentcaneffectivelymodifythesurfacedefectstatesof4H-SiCandimproveitselectricalcontactproperties.Thedefectstatecontroliscriticalforachievinghigh-performance4H-SiCdevices.TheresearchresultshaveimportantpracticalimplicationsforthedevelopmentandapplicationofSiC-basedelectronicdevices。4H-SiCisapromisingsemiconductormaterialforhigh-powerandhigh-temperatureelectronicdevicesduetoitsexcellentphysicalandchemicalproperties.However,thepresenceofsurfacedefectsinSiCcansignificantlyaffecttheelectricalpropertiesandreliabilityofSiC-baseddevices.Therefore,itiscrucialtocontrolandreducethedensityofsurfacedefectsinSiCforachievinghigh-performanceelectronicdevices.Inthisregard,avarietyofsurfacetreatmenttechniqueshavebeenexploredtoimprovethesurfacequalityofSiC.

Amongvarioussurfacetreatmenttechniques,ArFexcimerlasertreatmenthasemergedasapromisingtechniquetomodifythesurfacedefectstatesofSiC.TheprinciplemechanismbehindtheArFexcimerlasertreatmentisthephotochemicalreactioninducedbyphotonsfromthelaserbeam.ThephotonsabsorbedbytheSiCsurfacegeneratehighlyreactivespeciesthatreactwithsurfaceatomsandmodifythesurfacechemicalcompositionandstructure.TheArFexcimerlasertreatmentcaneffectivelyremovethesurfacecontaminantsandinducechangesinthesurfacemorphology,crystalstructure,anddefectstatesofSiC.

SeveralstudieshaveshownthatArFexcimerlasertreatmentcansignificantlyimprovetheelectricalcontactpropertiesofSiCbyreducingthedensityofsurfacedefects.Forexample,Wangetal.(2018)reportedthatArFexcimerlasertreatmentcanreducethedensityofinterfacestatesinmetal/SiCcontactsandimprovetherectifyingpropertiesofSchottkydiodes.Theimprovementwasattributedtotheremovalofsurfacecontaminationsandthereductionofdefectstatesnearthemetal/SiCinterface.

Similarly,Chenetal.(2020)demonstratedthatArFexcimerlasertreatmentcanreducethesurfaceroughnessandimprovethemorphologyof4H-SiCsurfaces.Thetreatmentalsoreducedthedensityofdeep-leveldefectsinSiC,whichenhancedtheconversionefficiencyofSiC-basedsolarcells.ThestudyalsoproposedthattheincorporationofcarbonatomsintotheSiClatticeduringtheArFexcimerlasertreatmentcouldplayasignificantroleinreducingthedensityofdeepleveldefectsattheSiCsurface.

ArFexcimerlasertreatmenthasalsobeenemployedtoimprovethesurfacequalityofSiCsubstratesforepitaxialgrowthofSiCthinfilms.Forexample,Wangetal.(2016)reportedthatArFexcimerlasertreatmentcansignificantlyreducethesurfaceroughnessanddislocationdensityof4H-SiCsubstrates.TheimprovedsurfacequalityofSiCsubstratesresultedinareducedthreadingdislocationdensityinthegrownSiCthinfilms,whichimprovedtheelectricalandopticalpropertiesofSiC-baseddevices.

Inconclusion,ArFexcimerlasertreatmentcaneffectivelymodifythesurfacedefectstatesof4H-SiCandimproveitselectricalcontactproperties.Thedefectstatecontroliscriticalforachievinghigh-performance4H-SiCdevices.TheresearchresultshaveimportantpracticalimplicationsforthedevelopmentandapplicationofSiC-basedelectronicdevices.FurtherstudiesareneededtoexplorethefundamentalmechanismsinvolvedintheArFexcimerlasertreatmentofSiCandoptimizethetreatmentparametersforachievingthedesiredsurfacepropertiesofSiC。InadditiontotheArFexcimerlasertreatmentmethodmentionedearlier,therearevariousothertechniquesavailableforthesurfacemodificationofSiC.Onesuchpopulartechniqueistheplasmatreatmentmethod.PlasmatreatmentisaprocessinwhichthesurfaceofaSiCsampleisexposedtoplasmageneratedinaplasmachamber.Thistreatmentisfoundtoenhancethesurfacewettability,surfaceenergy,andtheadhesionpropertiesofSiC.However,plasmatreatmentshouldbecarriedoutwithcautionasover-treatmentcanleadtotheformationofdefectsontheSiCsurface.

AnothertechniqueusedforsurfacemodificationofSiCischemicaltreatment.ThismethodinvolveschemicallyetchingSiCsurfacesusingacidssuchashydrofluoricacid(HF).ThistreatmentisfoundtoimprovetheadhesionpropertiesofSiC,enhanceitssurfacewettability,andremovesurfacecontamination.Chemicaltreatmentcanalsobecarriedoutusingbasicsolutionssuchaspotassiumhydroxide(KOH).However,thismethodislimitedtospecificSiCcrystalorientationsandtemperatures.

IonbeamimplantationisanothermethodusedforsurfacemodificationofSiC.Inthismethod,abeamofionsisdirectedtothesurfaceofSiC,andtheionspenetratetheSiCsurfaceandcreatedefects.ThedefectscreatedinthiswaycanmodifythesurfacepropertiesofSiCandenhanceitselectricalproperties.

InConclusion,surfacemodificationtechniquesareessentialinimprovingtheperformanceofSiC-basedelectronicdevices.Thesetechniquescanimprovetheelectrical,mechanical,andadhesionpropertiesofSiCwhicharecriticalforhigh-performancedevices.However,itisessentialtooptimizethetreatmentparametersandconditionstoachievethedesiredsurfacepropertiesofSiC。Moreover,itisimportanttonotethatsurfacemodificationtechniquescanalsohaveasignificantimpactontheenvironmentalstabilityofSiC-baseddevices.Forinstance,somesurfacetreatmentsmayenhanceSiC'sresistancetooxidation,humidity,andcorrosiveenvironments.Thisisparticularlyimportantforapplicationssuchasautomotive,aerospace,andhigh-temperatureelectronics,whereSiC-baseddevicesneedtooperatereliablyunderharshconditions.

Inadditiontotheaforementionedtechniques,thereareothersurfacemodificationmethodsthatcanbeexploredforSiC.Forinstance,surfacepatterningtechniquessuchasionbeametching,laserablation,andphotolithographycanbeusedtocreatemicro-andnano-patternsonSiCsurfaces.Thesepatternscanmodifythesurfaceroughness,wettability,andadhesionpropertiesofSiC,andcanbeusedtoenhancetheperformanceofSiC-basedsensors,filters,andMEMSdevices.

Inconclusion,surfacemodificationtechniquesplayacrucialroleinimprovingtheperformanceofSiC-basedelectronicdevices.ThesetechniquescanenhanceSiC'selectrical,mechanical,andadhesionproperties,aswellasitsenvironmentalstability.Ongoingresearcheffortsarefocusedonoptimizingthetreatmentparametersandconditions,developingnewsurfacemodificationmethods,andexploringthepotentialofsurfacepatterningtechniquesforSiC.Withcontinuedadvancementsinsurfacemodificationtechniques,SiC-baseddevicesarepoisedtoplayakeyroleinnext-generationelectronics,powerelectronics,andsensorsystems。Inadditiontosurfacemodificationtechniques,advancementsinSiCprocessingandfabricationarealsocontributingtothedevelopmentofhigh-performanceSiC-baseddevices.OneareaofresearchisthedevelopmentofnovelSiCcrystalgrowthtechniquestoproducelarge,high-qualitysinglecrystalswithreduceddefects,impurities,andstrains.Theseeffortsarefocusedonimprovingthecrystalgrowthprocess,optimizingthegrowthconditions,anddevelopingnewgrowthmethodologies,suchassolutiongrowthandhydridevaporphaseepitaxy.

AnotherareaofresearchisthedevelopmentofnewSiCprocessingtechniques,suchashigh-energyballmilling,sparkplasmasintering,andlaserprocessing,toimprovethemechanicalandthermalpropertiesofSiCmaterials.ThesetechniquesallowfortheproductionofSiCmaterialswithimprovedstrength,toughness,wearresistance,andthermalconductivity,whicharecriticalforhigh-performanceapplicationssuchasaerospace,defense,andenergy.

ThedevelopmentofSiC-baseddevicesisalsobeingdrivenbyadvancesindevicedesign,includingtheuseofnewmaterialsystemsandarchitectures.Forexample,theintegrationofSiCwithothermaterials,suchasgraphene,boronnitride,anddiamond,isbeingexploredtoenhancetheperformanceandfunctionalityofSiCdevices.Moreover,theuseofnoveldevicearchitectures,suchasverticalpowerMOSFETs,SiC-basedintegratedcircuits,andSiC-basedsensors,isbeinginvestigatedtofurtherleveragetheadvantagesofSiCandenablenewapplicationsthatarenotpossiblewithconventionalmaterials.

Overall,thedevelopmentofSiC-baseddevicesisarapidlyevolvingfieldthatofferstremendouspotentialforhigh-performanceelectronics,powerelectronics,andsensorsystems.Asnewmaterials,processingtechniques,anddevicearchitecturescontinuetoemerge,SiC-baseddevicesareexpectedtoplayanincreasinglyimportantroleinawiderangeofapplications,fromelectricvehiclesandrenewableenergysystemstoaerospaceanddefense。Inadditiontoitspotentialforhigh-performanceelectronics,powerelectronics,andsensorsystems,SiC-baseddevicesalsoofferseveraladvantagesovertraditionalsemiconductormaterials.Forone,SiChasawiderbandgapthansilicon,whichmeansitcanoperateathighertemperaturesandvoltageswithoutbreakingdown.Thismakesitidealforuseinhigh-power,high-temperatureapplicationssuchaselectricvehicleinverters,industrialmotordrives,andgrid-tiedinvertersforrenewableenergysystems.

SiCalsohasahigherthermalconductivitythansilicon,whichmeansitcandissipateheatmoreeffectively.Thisisparticularlyimportantinpowerelectronicsapplications,whereheatdissipationcanbeamajorchallenge.Inaddition,SiCdeviceshavelowerswitchinglossesthansilicondevices,whichmeanstheycanswitchonandofffasterandmoreefficiently.Thismakesthemidealforuseinhigh-frequencypowerapplicationssuchasRFandmicrowaveamplifiers.

AnotheradvantageofSiC-baseddevicesistheirabilitytooperateinhigh-radiationenvironments.Thismakesthemidealforuseinaerospaceapplicationssuchassatellitesandspacecraft,wheretheycanwithstandtheha