Degradation Dependency Analysis and Modeling of 1700 v Planar-Gate SiC MOSFETs under Gate Switching Instability

Silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (mosfets) are becoming increasingly prevalent in various power electronic applications. However, their widespread adoption is hindered by significant reliability issues related to the gate oxide. The threshold voltage drift under alternating gate bias, commonly referred to as gate switching instability (GSI), presents a substantial challenge to reliability. Given the widespread use of SiC mosfets in power converters, researching GSI is of practical significance compared to conventional bias temperature instability. This study systematically investigated the dependence of 1700 V planar-gate SiC mosfets on factors, such as gate bias, temperature, and switching time, and also provided the form of acceleration factor based on the physical explanation. Based on this, an accelerated degradation model was developed to quantify the impact of stresses on GSI for the first time. This research enhances the understanding of GSI and establishes a foundational framework for modeling and predicting the degradation of SiC mosfets under GSI.