A Novel Approach to Inactivate the Body p-i-n Diode of SiC MOSFET by Using the Normally-OFF JFET

Abstract

A novel approach to inactivate the body p-i-n diode of silicon carbide (SiC) MOSFET is proposed in this article. It features a normally-OFF JFET structure embedded medially between the two p-well regions in the z-direction. When the SiC MOSFET operates in the first quadrant, the normally-OFF JFET is pinched-off, guaranteeing the excellent fundamental performance of the SiC MOSFET. While when the SiC MOSFET serves as the freewheeling diode, the channel of the normally-OFF JFET is turned on, which provides a unipolar current conduction path with low cut-in voltage, thereby inactivating the body p-i-n diode. TCAD simulation results show that, in comparison with the double trench SiC MOSFET, the cut-in voltage and the reverse recovery charge of the proposed SiC MOSFET could be reduced by 51.6% and 52.2%, respectively.