Numerical demonstration of SiC trench MOSFET with integrated heterojunction diode for enhanced performance

Abstract

Abstract In this paper, a novel SiC trench-gate MOSFET with integrated heterojunction diode (HD-TG-MOS) is proposed and studied according to TCAD simulations. The n-type polysilicon/n-type SiC HD is introduced into the groove by the direct contact between the polysilicon and semiconductor. As a result, significant improvements of device performance in the first and third quadrants are observed as compared to the conventional SiC trench-gate MOSFET (C-TG-MOS). Better yet, aided by the extremely low barrier height across the heterojunction, the knee voltage reduces to only 0.5 V with comparison of that of ∼2.7 V for the body diode, when used for reverse freewheeling. These promotions make SiC HD-TG-MOS more advantageous for HF power conversion applications. In addition, another cell architecture variant adopting a similar concept is presented, and the according process implementation is addressed as well from viewpoint of manufacture.