Improved performance of 3D tri-gate 4H-SiC MESFETs with recessed drift region

An improved 3D tri-gate 4H-SiC MESFETs structure with recessed drift region was proposed. The recessed drift region of the proposed structure is to reduce the channel thickness between gate and drain to increase breakdown voltage as well as to eliminate gate depletion layer extension to source/drain to decrease gate-source capacitance. The DC and RF electrical characteristics of the proposed structure were studied in detail by numerical simulation. The simulated results showed that the maximum theoretical output power density of the proposed structure is about 19% larger than that of the published 3D tri-gate structure. The cut-off frequency (f_T) and the maximum oscillation frequency (fmax) of the proposed structure are 19.3 GHz and 74.1 GHz compared to 16.1 GHz and 55.9 GHz of those of the published 3D tri-gate structure, respectively.