为了研究Al组分对AlxGa1-xN/GaN高电子迁移率晶体管(High Electron Mobility Transition,HEMT)性能的调控作用,采用Silvaco TCAD软件建立了AlxGa1-xN/GaN HEMT数值计算模型,通过数值计算的方法研究了Al组分对AlxGa1-xN/GaN异质结的能带、极化电荷、二维电子气(two-dimensional electron gas,2DEG)及其输运特性、器件转移特性、输出特性的影响.得到了势阱深度、极化电荷面密度、2DEG浓度、沟道电子迁移率、阈值电压、峰值跨导、漏极电流随着Al组分的变化规律,并利用极化、能带、器件物理相关理论对结果进行了分析与讨论.结果表明:势阱深度、极化电荷面密度、2DEG面密度都随着Al组分的增加而增加;沟道电子迁移率随着组分的增加而减小;Al组分较小时,阈值电压绝对值、漏极电流随着Al组分的增加而增加,Al组分较大时阈值电压绝对值、漏极电流随着Al组分的增加而减小;Al组分为0.35时的峰值跨导高达124 mS.
Regulation of the Properties of AlxGa1-xN/GaN High Electron Mobility Transistor by Al Component
In order to study the effect of Al component on the performance of AlxGa1-xN/GaN high electron mobility transistor(HEMT),the numerical calculation model of AlxGa1-xN/GaN HEMT is established by using Silvaco TCAD software.The effection of Al component on the energy band,polarization charge,two-dimensional electron gas(2DEG)and its transport characteristics,device transfer char-acteristics and output characteristics of AlxGa1-xN/GaN heterojunction are studied by numerical calculation,and the variation rules of the potential well depth,the polarization charge surface density,the 2DEG concentration,the channel electron mobility,the threshold voltage,the peak transconductance and the drain current with Al component are obtained.The results are analyzed and discussed by using po-larization,energy band and device physics theories.The results show that the depth of the potential well,the surface density of polarized charge and the surface density of 2DEG all increase with increasing Al component;the channel electron mobility decreases with the increasing Al component;when the Al component is small,the absolute value of threshold voltage and drain current increase with increasing Al componen,but when the Al component is large,the absolute value of threshold voltage and drain current decrease with increasing Al component;the peak of the transconductancet is up to 124 mS when the Al component is 0.35.
AlxGa1-xN/GaN HEMTAl componentheterojunctiontwo-dimensional electron gas concentrationtransfer characteris-ticsoutput characteristic
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