Numerical study on thermal stability performance of 4H-SiC MOSFETs

Abstract

4H-SiC MOSFETs offer superior performance and reliability in extreme conditions, making them a great option for high-power and
high-temperature applications. However, thermal stability issues still hinder device performance improvements, which impact
threshold stability, interface quality, and reliability. This work explores the issue by employing a 2D model that collectively integrates
and disentangles the roles of electrical, thermal, and structural properties of 4H-SiC MOSFETs using COMSOL Multiphysics. Important
electrical metrics are retrieved and examined under various heat conditions. The findings indicate that the Vth decreases from 3.05 to
2.80 V with increasing temperatures. On the other hand, the subthreshold slope rises noticeably from 41 mV/dec to 126 mV/dec with
temperature. The results support the necessity of thermal control in the operational characteristics of 4H-SiC MOSFETs.