# A Two-Dimensional Computer-Aided Design Study of Unclamped Inductive Switching in an Improved 4H-SiC VDMOSFET

## TL;DR

This paper studies an improved SiC MOSFET design to enhance reliability in high-power applications.

## Contribution

The study introduces an improved VDMOSFET with better unclamped inductive switching performance and lower on-resistance.

## Key findings

- The improved VDMOSFET shows better UIS performance than conventional B-VDMOSFET.
- The modified device has a smaller on-resistance at room temperature.
- The design offers improved reliability for high-avalanche scenarios.

## Abstract

Due to its high thermal conductivity, high critical breakdown electric field, and high power, the silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) has been generally used in industry. In industrial applications, a common reliability problem in SiC MOSFET is avalanche failure. For applications in an avalanche environment, an improved, vertical, double-diffused MOSFET (VDMOSFET) device has been proposed. In this article, an unclamped inductive switching (UIS) test circuit has been built using the Mixed-Mode simulator in the TCAD simulation software, and the simulation results for UIS are introduced for a proposed SiC-power VDMOSFET by using Sentaurus TCAD simulation software. The simulation results imply that the improved VDMOSFET has realized a better UIS performance compared with the conventional VDMOSFET with a buffer layer (B-VDMOSFET) in the same conditions. Meanwhile, at room temperature, the modified VDMOSFET has a smaller on-resistance (Ron,sp) than B-VDMOSFET. This study can provide a reference for SiC VDMOSFET in scenarios which have high avalanche reliability requirements.