Low leakage current and high unipolar current density in a 4H-SiC trench gate MOSFET with integrated Schottky barrier diode

Abstract

This paper reveals a 4H-SiC Schottky barrier diode (SBD) integrated trench gate MOSFET with p-buried-layers (BLSI-MOS) by numerical simulations. In comparisons to the double-trench MOSFET (DT-MOS) and the trench-SBD-integrated MOSFET (TSI-MOS), the proposed device exhibits the superior tradeoff between first- and third-quadrant characteristics of SiC MOSFET. Furthermore, the BLSI-MOS features low electric field at the trench corner and the Schottky contacts, allowing extremely low off-state leakage current at 225 °C. The proposed structure also embodies the superiority of low gate charge and reduced output capacitance compared with the DT-MOS and TSI-MOS. These results demonstrate that the BLSI-MOS is a new prototype device to obtain substantial success in SiC SBD-integrated MOSFET for high temperature and high efficiency power module applications.