Abstract: Atwo-dimensionalelectro-thermalmodelofthetypicalHEMTwasestablishedbysimulationsoftwareSentaurus-TCAD.Mobilitydegradationinhighelectricfield,Avalanchegenerateeffectandself-heatingeffectwereconsidered,byanalyzingthedistributionsandvariationsoftheelectricfield,thecurrentdensityandthetemperature,adetailedinvestigationofthedamageeffectandmechanismofhighpowermicrowave(HPM)onAlGaAs/GaAspseudomorphichigh-electron-mobilitytransistor(pHEMT)undertheinjectionof14.9GHzequivalentvoltagesignalsfromthedrainelectrodewasperformed.Thesimulationresultssuggestthatintrinsicexcitation,avalanchebreakdown,thermalbreakdownallcontributetodamageprocess,thetemperaturebehavesasperiodic“increasing-decreasing-increasing”oscillationandthewholetrendcontinuouslyincreaseswithtimeanditdecreasesduringpositivehalfcycleandincreasesduringnegativecycle.Thegatecurrentdensityappearsdoublepeakphenomenonbecauseavalanchebreakdownandthermalexcitation.Heataccumulationoccursduringthenegativehalfcycleandbelowthegatenearthedrainsideismostsusceptibletoburnout.Meanwhile,thedrainterminalseriesresistancecanenhancethecapabilityofthedevicetowithstandmicrowavedamageeffectively.

Key words: highpowermicrowave, highelectronmobilitytransistor, damagemechanism, drainelectrode, failureanalysis