1200V SiC MOSFETs Under Dynamic Reverse Bias Testing in High-Temperature and High-Frequency Environments

Silicon carbide (SiC) MOSFETs are widely used in high-voltage and high-temperature applications, however, their reliability under dynamic operating conditions remains a concern. In this work, three types of commercial 1200 V SiC MOSFETs with different structures were evaluated using a dynamic high-temperature reverse bias (DHTRB) test. The test was conducted at 25 °C and 175 °C, with switching frequencies of 50 kHz and 100 kHz for 168 hours. Real-time drain leakage current was monitored, and key static parameters were measured before and after the test. The results show that temperature had a more pronounced effect on parameter variation. The trench-gate device experienced a larger reduction in breakdown voltage. Among the two planar-gate devices, one exhibited threshold voltage shift and increased leakage current at high temperature, while the other maintained stable performance across all test conditions. This study provides useful insights for the structural design and reliability evaluation of SiC MOSFETs under dynamic stress conditions.