Design and Fabrication of 4H-SiC RF MOSFETs

We present simulations, fabrication and analysis of 4H-SiC RF power MOSFETs. We obtain an extrinsic transition frequency of 11.2 GHz and an /max = 11.9 GHz, a breakdown voltage above 200 V and an output power of 1.9 W/mm at 3 GHz. The measured devices are double fingered, source-gate-drain-gate-source with 2times0.4 mm total gate width and the nominal channel length of the devices is 0.5 mum. To the authors knowledge, this is the highest transition frequency and output power density ever reported for SiC RF MOSFETs. The antipunch through is introduced as a way to take advantage of the SiC's material properties. A detailed description of the device processing is also given.