A Novel 4H-SiC Trench MOSFET Integrated With Mesa-Sidewall SBD
Zhonglin Han, Yun Bai, Hong Chen, Chengzhan Li, Jiang Lu, Chengyue Yang, Yao Yao, Xiaoli Tian, Yidan Tang, Guan Song, Xinyu Liu
Abstract
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.