Modeling of SiC MOSFET Behavior in Short-circuit Transient Considering Gate Leakage Current

Abstract

In the reproduction of SiC MOSFET short-circuit behavior, one major issue that remains is the absence of a proper gate current model, which in tests strongly depends on device temperature. This paper discusses potential mechanisms and determines its origin as thermionic emission effect. By introducing the thermionic current to the classic semiconductor drift-diffusion framework that is coupled with lattice self-heating effect, dynamic gate leakage current development can be mirrored in simulation. Results also shed light on the possible failure physics by revealing the hotspot location, and practical concerns between two unmatched cells. In essence, this modeling method can also be applied to other similar high-temperature operations of SiC MOSFETs.