High-frequency noise performance of SiGe p-channel MODFETs

Abstract

For the first time, an investigation into the microwave noise performance of SiGe-based MODFETs is presented. The devices were 0.1 µm gate-length p-channel MODFETs fabricated on a high-mobility SiGe strained-layer heterostructure grown by UHV-CVD and had a unity gain cutoff frequency fT of 42 GHz and maximum frequency of oscillation fmax of 69 GHz at a drain-to-source bias voltage Vds of –0.6 V. A minimum noise figure Fmin of 1.1 dB and an associated gain Ga of 18 dB were obtained at 3 GHz, while values of Fmin = 1.7 dB and Ga = 12 dB were obtained at 10 GHz. These values are comparable to those of SiGe production HBTs, and demonstrate the suitability of SiGe MODFETs for RF and microwave communications applications.