Improved Clival Gate 4H-SiC MESFET with Recessed Drain Drift Region and Recessed P-Buffer Layer

Abstract

An improved clival gate 4H-SiC MESFET with recessed drain drift region and recessed p-buffer layer (RDRPCG MESFET) was proposed in this paper. The key improvement in this paper is the enhancement of the drain current and the breakdown voltage. The recessed drain drift region and recessed p-buffer layer are introduced in the proposed structure to ensure the rise of the drain current and the breakdown voltage simultaneously. DC and RF characteristics are simulated and compared to the clival gate 4H-SiC MESFET (CG MESFET). The numerical simulated results show that the breakdown voltage is 116.3V compared to 76.6V of CG MESFET, which is about 51.8% larger than that of CG MESFET. There is an 11.9% increase in drain saturation current of RDRP-CG MESFET compared with CG MESFET. Thus, the maximum output power density is about 70% larger than that of CG MESFET, which is due to the increase in drain saturation current and breakdown voltage. There is a slight decrease in cut-off frequency in the proposed structure. Keywords-component; 4H-SiC MESFET; DC characteristics; RF characteristics