Improved Characteristics of 4H-SiC MESFET with Multi-recessed Drift Region

4H-SiC MESFET with multi-recessed drift region is proposed and the DC and RF characteristics are analyzed in this paper by 2D numerical simulation. The simulated results show that the breakdown voltage is about 68% larger than that of the conventional structure. The calculated maximum output power density at operation point VGS=-10V, VDS=40V are 9.6W/mm and 6.2W/mm respectively for 4H-SiC MESFETs with multi-recessed drift region structure and conventional structure. The multi-recesses eliminate the spaces adjacent to gate and stopped the depletion region extending towards drain and source. Compared to the conventional structure, the gate-source capacitance (CGS) and drain-gate capacitance (CDG) of multi-recessed drift region structure have both been reduced, which will result in a superior RF performance.