Experimental Demonstration on Superior Switching Characteristics of 1.2 kV SiC SWITCH-MOS

Abstract

A 1.2kV silicon carbide (SiC) SBD-wall-integrated trench MOSFET (SWITCH-MOS) had been proposed and fabricated in order to solve body-PiN-diode related problems such as bipolar degradation and reverse recovery loss. In this paper, switching characteristics of turn-on and turn-off of the SWITCH-MOS are investigated and discussed in comparison with conventional trench MOSFET structures with p+ region at trench gate bottom (IE-UMOSFET) and without the p+ region (named “device A” in this paper). The SWITCH-MOS shows an extremely small turn-on loss and turn-off loss because of the high dV/dt and little reverse recovery current. In addition, it is found that the SWITCH-MOS exhibits smaller turn-off loss than “device A” at almost the same dJ/dt, which means that drain surge voltage was suppressed effectively while keeping the smaller turn-off loss.