Simulation of high-power 4H-SiC MESFETs with 3D tri-gate structure

Abstract

A novel 3D tri-gate 4H-SiC MESFET structure is proposed for high-power RF applications. In comparison with the conventional structure, improved saturation drain current is obtained owing to the formation of a vertical channel, which induces device equivalent channel width increase. The output power density of the proposed structure with t=2 µm, a=0.4 µm and w=0.6 µm is 15.5 W/mm compared to 4.2 W/mm for the conventional one and yet it maintains almost the same cutoff frequency (fT) and maximum oscillation frequency (fmax).