Evaluation of reverse recovery characteristic of silicon carbide metal–oxide–semiconductor field‐effect transistor intrinsic diode

Abstract

To use the silicon carbide (SiC) metal–oxide–semiconductor field-effect transistor (MOSFET) intrinsic diode as a freewheeling diode in a power converter, its reverse recovery characteristics should be carefully evaluated from the point view of application. The intrinsic diode is based on the p–i–n junction structure, thus the minority carrier will inject into the drift layer during the forward conduction period, which leads to reverse recovery current when it switches off. The turn-off voltage, forward current, current commutating slope (di/dt) and junction temperature are major factors affecting the turn-off process of a diode, and are mostly concerned in practical applications. Therefore, in this study, the reverse recovery characteristics of the intrinsic diode are systematically evaluated based on these four factors. The experimental results are presented and discussed. The reverse recovery characteristics of an SiC Schottky barrier diode (SBD) and two types of silicon (Si) p–i–n diode are also presented for a quantitative comparison. In terms of the reverse recovery performance, although not as good as the SiC SBD, the SiC MOSFET intrinsic diode is much better than the Si p–i–n diode.