Performance Evaluation of the Body-Diode of SiC Mosfets under Repetitive Surge Current Operation

In power electronic applications the replacement of the state-of-art Si-based IGBTs by SiC-based Mosfets can bring improvements to the performance metrics of several systems, such as higher efficiency and increased power density. Currently, the cost of SiC semiconductor technology is far greater than that of Si-based devices. Therefore, the utilization of the intrinsic body-diode of the Mosfet chips as replacement of any additional anti-parallel SiC Schottky diode chips makes economic sense. Unfortunately, little information about the body-diode ruggedness is available in the datasheets or in the literature, which leads to concern about the device long term reliability. This article verifies the robustness of the body-diodes of three commercial SiC Mosfets in 10 μs short surge current operation with additional 80% rated reverse blocking voltage after surge. The results show that the tested semiconductors can impressively withstand several times their rated current without showing signs of degradation.