Recent Developments in Understanding the Gate Switching Instability in Silicon Carbide MOSFETs

Silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) are becoming increasingly important in numerous renewable energy applications that inherently involve electric power conversion. These applications typically require continuous switching of the gate voltage at frequencies up to hundreds of kilohertz, at which the use of SiC MOSFETs is particularly beneficial.Here, we discuss the gate switching instability, which is a component of the threshold voltage drift, inherently present in all commercial SiC MOSFETs. It arises exclusively under continuous gate switching with bipolar voltage levels, whereby the properties of the gate switching instability differ significantly from those of conventional bias temperature instability. After a review of these defining properties, we discuss the two prevalent mechanisms that have been suggested and discuss their conformity with experimental findings.