AlGaNGaN MOS-HEMT器件特性研究

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1、摘要摘要国内外的研究报道表明，高性能AIGaN／GaN异质结器件在大功率微波领域的应用有较大的优势，然而从AIGaN／GaN异质结器件诞生以来伴随的界面缺陷、陷阱电荷以及较大的栅泄漏电流等问题严重制约了这种器件的应用。因此，针对抑制栅泄漏电流和减少表面态的绝缘介质钝化工艺和金属氧化物半导体(MOS)结构就成为研究的热点。另外，GaN作为宽禁带半导体材料有高温应用的优势，AIGaN／GaN异质结器件的温度特性研究也至关重要。本文采用原子层淀积(ALD)实现了10rimA1203为栅介质的高性能AIGaN／GaN金属氧化物半导体高电子迁移率晶体管(MOS．HEMT)。通过

2、对MOS．HEMT器件和传统MES—HEMT器件室温特性的对比，验证了新型MOS-HEMT器件饱和电流和泄漏电流的优势。通过分析MOS．HEMT器件在30．180℃之间特性的变化规律，与国内报道的传统MES．HEMT器件随温度退化程度对比，发现了器件饱和电流和跨导的退化主要是由于输运特性退化造成的。另外本文分析了电容随温度变化曲线时发现，两种器件有较大的不同，作者假设为A1203与A1GaN之间良好的接触特性减少了表面陷阱电荷，通过拟合阈值电压随温度的变化曲线，定量证明了这个结论。从而全面说明了栅介质减小了引入A1GaN界面的表面态是提高特性的重要原因。关键词：AIG

3、aN／GaNHIEMT，原子层淀积O扎D)，陷阱电荷，温度特性AbstractRecentprogressinAlGaN／GaNHeterostructureFieldEffectTransistors(HFETs)hasdemonstratedthattlleyarekeydevicesforhi}gh-powermicrowaveapplication．However,manyquestionsrelatedtothematerialqualitysuchasdefectstatesandtrappingeffectsinaheterostructureandfo

4、llowingdeviceperformancereliabilityalestillopen．PassivatedHFETswithagateinsulator,metal-oxidesemiconductor(MOS)rnPETsarethereforeundersystematicstudiesbecausetheyleadtosmallergateleakagecurrentandallowthesuppressionofsurfacestatedefectsandthusincreaseintheoutputpower．Ontheotherhand，high

5、bandgapofGaNopensanapplicationareafordevicestheyCanoperateatelevatedtemperatures．Inthispaper,aMetalOxideSemiconductorHigh—Electron-MobilityTransistor(MOS—HEMT)、衍thAtomicLayerDeposition(ALD)10nmA1203gatedielectricismanufactured．nesuperioritiesonsaturationcurrentandleakagecurrentofthenove

6、lMOS—HEMTdevicesaleverifiedthroughroomtemperaturecharacteristicscontrastoftheMOS．HEMTandtraditionalMES．HEMTdevices．T11iSpaperalsoillustratesthestaffsticsanalysisofthedevicefeaturevariationat30．180℃range．whichshowsthedistinctionofdegradationdegreebytemperaturebetweenthetwokindsofdevices．

7、Thus。theconclusionthatthedevicesaturationcurrentsandthetransconductancedegradationsalemainlycausedbytransportcharacteristicdegradationcallbesummarized．Dependenceofcapaticanceontemperatureshowsdifferenceinthetwokindsofdevices，whichissupposedthat，thenumberoftrapsinthesurfacebetwe