A High-Reliability SiC Trench MOSFET With Enhanced Reverse Conduction and Short-Circuit Capability

A novel asymmetric silicon carbide (SiC) trench Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) integrating lateral junction barrier Schottky diode (LJ-ATMOS) with enhanced reverse conduction and short-circuit capability is proposed. The LJ-ATMOS features a deep source trench on the right side of the gate and an integrated junction barrier Schottky (JBS) diode at the bottom of the gate. Meanwhile, the P+ region combined with the deep P-well on the left side forms a self regulating region. In reverse conduction , the electrons in the drift region are conducted through the JBS to the source terminals. Simulation results show that the LJ-ATMOS not only exhibits a 2.0-fold lower turn-on voltage (Von) than the parasitic body diode, but also effectively eliminates the bipolar degradation issues. More importantly, the self-regulating region of the LJ-ATMOS effectively clamp the saturation current contributed by the MOS channel and Schottky contact under short-circuit conditions. The results show that the short-circuit withstand time (tsc) of LJ ATMOSshows a 2.1-fold improvement compared to conventional asymmetric trench MOSFET (C-ATMOS). In addition, due to the shielding effect of the deep P+ region, the LJ-ATMOS also exhibits ultra-low oxide electric field, reverse recovery charge (Qrr), gate-drain charge (Qgd), and capacitance (Cgd).