A low loss single-channel SiC trench MOSFET with integrated trench MOS barrier Schottky diode

Abstract

A single-channel SiC trench MOSFET (SC-TMOS) with integrated trench MOS barrier Schottky diode (TMBS) is proposed and investigated in this paper. The electric field at the Schottky interface is reduced to 0.37 MV cm−1 by the trench MOS and P+ shield under the gate, which completely suppresses the leakage current through the TMBS. The on-state voltage drop (V R_ON) of the SC-TMOS in reverse conduction state is reduced to 1.59 V (@J SD = 400 A cm−2) compared to 2.93 V of the PN body diode of a conventional trench MOSFET (C-TMOS) and 1.61 V of a three-level protection trench MOSFET (TP-TMOS). Meanwhile, higher BFOM (Baliga’s figure of merit: BV2/R on,sp) is obtained, which is 11.8% and 40% improved compared with those of the C-TMOS and TP-TMOS, respectively. Besides, the reverse recovery charge of the SC-TMOS is reduced by 41.7% and 66.4% compared with those of the C-TMOS with or without external junction barrier Schottky diode (JBS), and is comparable with that of the TP-TMOS. Moreover, with optimized design, C GS and C GD decrease dramatically. As a result, the total inductive switching loss of the proposed SC-TMOS is reduced by 19.5%, 43.2% and 28.8% compared with those of the C-TMOS with or without external JBS and TP-TMOS, respectively.