研制了一种T型栅长为90 nm的InP基In0.52Al0.48As/In0.65Ga0.35As赝配高电子迁移率晶体管(PHEMTs).该器件的总栅宽为2×25 μm,展现了极好的DC直流和RF射频特性,其最大饱和电流密度和最大有效跨导分别为894 mA/mm和1640 mS/mm.采用LRM+ (Line-Reflect-Reflect -Match)校准方法实现系统在1~110 GHz全频段内一次性校准,减小了传统的分段测试多次校准带来的误差, 且测试数据的连续性较好.在国内完成了器件的1~110 GHz全频段在片测试,基于1~110 GHz在片测试的S参数外推获得的截止频率ft和最大振荡频率fmax分别为252 GHz和394 GHz.与传统的测试到40 GHz外推相比,本文外推获得的fmax更加准确.这些结果的获得是由于栅长的缩短,寄生效应的减小以及1~110 GHz全频段在片测试的实现.器件的欧姆接触电阻率减小为0.035 Ω·mm.

In this paper, 90-nm T-shaped gate InP-based In0.52Al0.48As/In0.65Ga0.35As pseudomorphic high electron mobility transistors (PHEMTs) with well-balanced cut-off frequency ft and maximum oscillation frequency fmax are reported. This device with a gate-width of 2×25 μm shows excellent DC characteristics, including a maximum saturation current density Idss of 894 mA/mm, and a maximum extrinsic transconductance gm,max of 1640 mS/mm. The off-state breakdown voltage (BVoff-state) defined at a gate current of 1mA/mm is 3.3 V. The RF measurement is carried out covering the full frequency range from 1 to 110 GHz, an extrapolated ft of 252 GHz and fmax of 394 GHz are obtained, respectively. These results are obtained by the combination of gate size scaling, parasitics reduction and the on-wafer measurement in the full frequency band from 1 to 110 GHz.