透明栅algan2fgan+hemt器件制备与特性分析

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1、AbstmctIllAbstr．actAsthethird-generationsemiconductor，GaNpresents10tsofadvantages，such舔largeb卸dgap，hi曲thermalconductiVit)r，hi曲breakdownVoItage，mobilit)，觚dsaturationVeloci妙．T．11eref0陀，higheIectronmobilitytransistorS(HEMTs)basedonAlGaN／GaNheteros缸．ucturesarewidelyappIicatedforhig

2、htcmperaturc，highpower锄dhi曲舭qu朋cys鲫ic伽ductordeVices，hi曲嘶gh伽essLED，andhighperfornlanceultraViolet(UV)detector．Duet0theirhighcallrierconcentrationandopticalbandg叩，transparentconductiVeoxidethinfilmsexhibitexcellentopticalandelectricalpropenies．Inthisdissertation，thepropeniesofAlG

3、a_N／GaNHEMTdeViceswithtransparentgatematerialsofAZO(Al-dopedZincOxide)werestudied．Firstly，theAlGaN／GaNStructureandtheoperationmechanismofHEMTdeVic骼wereinVestigated．Basedonthetheo呵，AlG扑ⅣGa_NHEMTdeviceswithtransparentAZOgatewerefabricatedsuccess如lly，andtheirpropertiesincludingDCc

4、haracter．sticsandSchottkycharacteriSticswere锄aIysed．DepositingathinNi(10nm)layerbeforetheAZOcouldeffectiVelyreducethegateleakagecurrentandimproVetheSchottkybarrierhei曲t．Besides，itgaVeriset0ahi曲ersa_turationcu九．ent．TIlleinfluenceof豫pidthermala11neaIing(RTA)，UVi11radiation锄delect

5、ricalStressinthedevicesw弱aIsoinvestigatedinthisdisseIrtation．TheresultsshowedthatannealingatlowtempemtIlre，especially300℃，wouldsignificantlyimproVetheSch嘣kych棚．acteristics．Butseriousdegrada“onofthedevicVeswouldoccurduringannealingat400℃．UVimdiationcouldincreasetheoutputcurrent，

6、asareSultofmereleaseofeIectronscapturedbytrapsinthedevicesandthegeneratiollofphoto-inducedcarriers．W11at’simportantisthatthedeVicescharacteristicscouldnotrecoVercompletelyaRertheremovalofUVlight．Undertheon—stateStress，thehotelectronsinchannelwerecapturedbytrapsinthebarrierorbuf

7、俺rlayer，whichdepletedthetwo-dimensionalelectrongas(2DEG)andincreasedtheconductionresistance．Thisdegradationreducedthesaturationcullrentandpeaktransconductance．However'undertheoff-stateStress，thesaturationcullrentandtransconductanceincreased，andthethresholdVoltagenegatiVelydriRe

8、dsimultaneously．Thiswasduet0theinjectionofsomeelectron