Frequency and Temperature Performance Comparison on the AC BTI of Commercial SiC MOSFETs

Silicon carbide (SiC) MOSFET is currently widely used in many fields due to its several advantages, such as automotive drive train, solar inverter and aerospace applications. However, SiC MOSFET has always attracted much attention due to its poor gate oxide interface quality. One important way to determine the gate oxide quality is monitoring the drift in threshold voltage under AC bias temperature instability (AC BTI). Several teams have conducted comprehensive research on factors impacting on AC BTI. Two of the most important factors, frequency and junction temperature, may have different conclusions for different gate structures. Therefore, this paper uses three commercial gate structures of SiC MOSFET widely used nowadays as experimental device under test (DUTs), conducts experiments around the two influencing factors of frequency and temperature, and makes relevant conclusions and discussions on specific application fields.