High performance 4H-SiC MOSFET with deep source trench

Abstract

In this study, we investigated a 4H-SiC deep source trench metal-oxide semiconductor field-effect transistor (DST-MOSFET) using technology computer-aided design numerical simulations. The proposed DST-MOSFET comprises a P-pillar formed along with the DST and a side P+ shielding region (SPR), which replaces the gate trench bottom SPR. Owing to the superjunction generated by the P-pillar and N-drift region, the static characteristics of the DST-MOSFET were superior to those of the trench gate MOSFET (UMOSFET) and double-trench MOSFET (DT-MOSFET). The specific on-resistance and Baliga’s figure of merit of DST-MOSFET improved by 9% and 104%, respectively, in comparison with those of UMOSFET; and by 37% and 64%, respectively, compared to those of DT-MOSFET. Additionally, the SPR reduced the gate-to-drain capacitance of the DST-MOSFET and improved the switching characteristics. Consequently, the total switching energy loss of the proposed DST-MOSFET reduced by 63% and 47% in comparison with those of the UMOSFET and DT-MOSFET, respectively.