A SiC Trench MOSFET concept offering improved channel mobility and high reliability

Abstract

This work discusses the challenges in the design of a SiC Power MOSFET compared to their silicon-based relatives and describes a novel SiC Trench MOSFET concept. The most prominent difficulties being identified are related to the properties of the channel and the gate dielectric as well as their interface. Different approaches to realize a SiC MOSFET are briefly discussed and the CoolSiC™ MOSFET concept is introduced which balances low conduction losses with an IGBT-like reliability. Long term gate oxide tests reveal that the extrinsic failure rate can be confidently predicted to be less than 1 FIT per die in 20 years under specified use conditions for industrial applications.