A Novel 4H-SiC Trench MOSFET Integrated With Mesa-Sidewall SBD

SiC MOSFET integrated with Schottky barrier diode (SBD) can handle the reverse current during switching operation and reduce the package cost. However, the integrated SBD weakens the high-voltage-withstanding capability of the SiC MOSFET. In this article, a novel 4H-SiC trench MOSFET integrated with mesa-sidewall SBD (TMS-SBD) is proposed and studied with the 2-D simulation. Compared with the trench MOSFET integrated with the SBD locating on the mesa (TM-SBD), the TMS-SBD shows a larger breakdown voltage (BV), a lower electric field in the gate oxide, and a better tradeoff between BV and specific ON-resistance. The TMS-SBD also shows the same current capability as that of the TM-SBD. Due to the removal of one sidewall overlap between the gate electrode and drain electrode, the reverse capacitance of TMS-SBD is lower than that of the TM-SBD. In double-pulse test simulation, the turn-on loss and turn-off loss of the TMS-SBD reduce by 30% and 56% than those of the TM-SBD, respectively. Therefore, the TMS-SBD is a more attractive device in high-voltage, high-reliability, and low-switching-loss applications.