Comparative evaluation of surge current capability of the body diode of SiC JMOS, SiC DMOS, and SiC Schottky barrier diode

摘要

SiC Schottky barrier diode and SiC MOSFET’s body diode are two solutions for current freewheeling in the reverse direction. Recently, the monolithic Schottky barrier diode integrated SiC MOSFET (SiC JMOS) has been developed to achieve a higher utilization rate of the SiC chip area. However, the reliability of barrier diode integrated SiC MOSFET under surge current stress is a critical requirement that has to be taken into account for in power applications. In this paper, a comparative surge current capability evaluation between a SiC JMOS, SiC DMOS, and SiC Schottky barrier diode was presented. The experiment results show that the surge current capability of the SiC JMOS is weaker than that of the SiC DMOS but is better than the SiC SBD under the same current density condition. The gate breakdown is the critical factor limiting the reliability of the SiC JMOS and SiC DMOS under surge current stress. SiC JMOS show no significant degradation after up to 10k cycles repetitive surge current stress at 80% of surge current limit, while the SiC SBD is more likely to degenerate under repetitive surge current stress.