A novel stair-stepping buffer-gate 4H-SiC MESFET with multiple recesses in a buffer layer

A novel stair-stepping buffer-gate 4H-SiC MESFET with multiple recesses (SBG-MR 4H-SiC MESFET) is proposed for improving power characteristics. The main novelty of the SBG-MR 4H-SiC MESFET is that two recesses are introduced at the top of the p-type buffer layer, which ameliorates the electric field distribution and significantly increases saturation current density. The electron current and electric field line profile of the stair-stepping buffer-gate (SBG) and SBG-MR structures are simulated in order to evaluate the power characteristics. The results show that the saturation current density and the breakdown voltage of the SBG-MR structure are increased by 37.5% and almost 10%, respectively, and thus the power density is significantly improved by 55% with comparison to those of the SBG structure.