为了获得 T型栅应变高电子迁移率晶体管( mHEMT)器件，利用电子束(Electron beam， E-beam)光刻技术制备了 210 nm栅长，减小 mHEMT器件栅极的寄生电容和寄生电阻。采用 PMMA A4/ PMMA-MMA/PMMA A2三层胶电子束直写的方法定义了 210 nm栅长T型栅极。 InAlAs/ InGaAs异质结 GaAs-mHEMT器件的直流特性和高频特性分别通过 Agilent B1500半导体参数分析仪和 Agilent 360 B矢量网络分析仪测试。直流测试结果显示， 210 nm栅长InAlAs/InGaAs沟道GaAs-mHEMT单指器件的最大有效输出跨导( gm:max)为195 mS/mm，器件最大沟道电流 160 mA/mm。射频测试结果显示，电流增益截至频率( fT)和最高振荡频率( fmax)分别为 46 GHz和115 GHz。同时欧姆电极特性和栅极漏电特性也被表征，其中栅极最大饱和漏电流密度小于 1×10-8 A/μm。

Abstract：A conventional tri-layer resist structure which consists of PMMA A4/PMMA-MMA/PMMA A2 is adopted to pattern the 210 nm T-gate resist profile in a single lithographic step and a single development step，in order to fabricate the T-shaped gate InAlAs/InGaAs metamorphic High Electron Mobility Transistors(mHEMTs) on a GaAs substrate. The DC and microwave performance of the device are characterized on wafer by an Agilent B1500 semiconductor parameter analyzer and an Agilent 360 B Vector Network Analyzer under room temperature，respectively. The mHEMT device shows the DC output characteristics having an extrinsic maximum transconductance g m:max of 195 mS/mm and the full channel current of 160 mA/mm. The cut-off frequency f T and the maximum oscillation frequency f max for the mHEMT device with gate width of 50 μm are 46 GHz and 115 GHz，respectively. Meanwhile，work has also been carried out to determine the quality of the Ti/Pt/Au Schottky contact to InAlAs with remarkably small gate leakage current in the order of 1×10-8 A/μm，which is extremely useful for the reduction of shot noise and the LNA applications.