栅长为83-nm的毫米波低噪声InP基PHEMTs的研制

本文设计并实现了一种83-nm T型栅的InP基In0.52Al0.48As/In0.65Ga0.35As赝配高电子迁移率晶体管（PHEMT）。该器件的总栅宽为2×30μm，展现了良好的DC直流、RF射频以及低噪声特性，包括最大饱和电流密度Idss和最大有效跨导gm,max分别为894mA/mm和1640mS/mm。基于1~110 GHz全频段在片测试的S参数外推获得的最大截止频率ft和最大振荡频率fmax分别为247GHz和392GHz。测得的器件拐点（稳定因子k=1）频率为102GHz，因此，基于拐点外推获得的fmax更加准确。采用冷源法完成器件的在片噪声参数的测试，测得的最小噪声系数NFmin在30GHz时为1dB，相关增益Gass为14.5dB。这些良好结果的获得是由于沟道层中InAs摩尔组分的增加，沟道层厚度的减小，栅长的缩短以及寄生效应的减小。这些优良的特性使得该器件非常适合于毫米波频段低噪声单片集成电路的应用。

Design and implementation of 83-nm low noise InP-based InAlAs/InGaAs PHEMTs

83-nm T-shaped gate InP-based In_0.52Al_0.48As/In_0.65Ga_0.35As pseudomorphic high electron mobility transistors (PHEMTs) with excellent DC and RF performance as well as low noise characteristics are reported, including a maximum saturation current density I_dss of 894 mA/mm, a maximum extrinsic transconductance g_m,max of 1640 mS/mm, an extrapolated cutoff frequency f_t of 247 GHz and a maximum oscillation frequency f_max of 392 GHz which were based on the measured S-parameters from 1 to 110 GHz. The minimum noise figure (NF_{m min}) measured by the cold-source method is 1 dB at 30 GHz associated with a gain of 14.5 dB at V_ds of 0.8 V and I_ds of 17 mA. These results were obtained by the combination of increased InAs mole fraction in the channel, gate size scaling, parasitic reduction and the quantization channel. These excellent results make it one of the most suitable devices for millimeter wave (MMW) low noise applications.