Microwave characteristics of high f/sub max/ low noise thin film silicon-on-sapphire MOSFETs

We report the microwave characteristics and modeling of thin-film silicon-on-sapphire n- and p-channel MOS transistors with high f/sub max/, and low F/sub min/. N-channel and p-channel MOSFETs were fabricated with optically defined low resistance T-gates and found to have f/sub max/ values above 60 GHz and 40 GHz, respectively. The minimum noise figure, F/sub min/ was below 1 dB at 2 GHz for both devices. Both the f/sub max/ and F/sub min/ values are the best reported to date for silicon MOSFETs. A small signal model, similar to that used for MESFETs, is used here to model the devices, extract the small signal parameters and correlate the device structure with the measured performance.