A novel 4H-SiC MESFET with P-type doping zone and recessed buffer layer

Based on the double recessed 4H-SiC metal semiconductor field effect transistor (DR-MESFET) structure, a new 4H-SiC MESFET with p-type doping zone in drain drift region and recessed buffer layer under the source drift region (PDRB-MESFET) is proposed in this paper. The simulation results show that the breakdown voltage of this novel structure is improved by 63.76% compared with that of DR-MESFET. Thus, the maximum output power density of the device is increased by 72.85%. As for RF, the cutoff frequency decreases by 4.42% due to the increase of gate source capacitance, and RF performance deteriorates slightly. But in general, it is meaningful to exchange a slight decline in RF performance for a significant improvement in DC performance. The length and width of the p-type doping region are optimized and the optimal size of the p-type doping region is obtained.