SiC Trench MOSFET With Embedded Schottky Super Barrier Rectifier for High Temperature Ruggedness

In this article, a novel SiC trench MOSFET with integrated Schottky super barrier rectifier (SSBR-TMOS) is proposed and studied by TCAD simulations. The SSBR is introduced as a replacement of the body diode to improve the performance of the device in the third quadrant. It contains two parts. One is the MOS channel formed by filling the alternate groove with the source metal, and the other is the Schottky contact formed by the direct touch between the source metal and P-base region in the neighboring mesa. For forward conduction operation, the electrons must overcome the super barrier created by the MOS channel as well as the barrier produced by the Schottky contact before reaching the source. Therefore, the SSBR shows a Schottky-like characteristic to that of a Schottky barrier diode (SBD). More importantly, it possesses stronger high temperature ruggedness than the latter. Results demonstrate that the performance of SiC SSBR-TMOS in the first and third quadrants is as excellent as that of the SiC SBD-wall-integrated trench MOSFET (SWITCH-TMOS). Both show improvement when compared with that of the conventional SiC trench MOSFET (C-TMOS). Moreover, the short-circuit (SC) withstanding time (SCWT) and avalanche energy
${E}_{\text {AS}}$
of SiC SSBR-TMOS show improvement by a factor of 2 and 1.1, 7 and 4.5, respectively, as compared to those of the SiC C-TMOS and SWITCH-TMOS, indicating the great potential for high-frequency and harsh environment applications.