High Frequency 4H-SiC MOSFETs

Abstract

We present new results on 4H-SiC RF power MOSFETs. By improvements in device layout we obtain better high frequency performance compared to the first generation of devices. An extrinsic transition frequency fT=11.4 GHz was achieved and fmax=11.2 GHz for a device with 0.5 µm nominal channel length. Functional devices with 0.3 µm nominal channel length were also made. These devices gave fT=15.1 GHz and fmax=19.5 GHz but they have lower breakdown voltages and therefore lower overall performance. The measured devices are double fingered with 0.8 mm total gate width.