A Novel 4H-SiC Double Trench MOSFET with Built-In MOS Channel Diode for Improved Switching Performance

Abstract

This study proposed a novel 4H-SiC double trench metal-oxide-semiconductor field-effect-transistor (DTMCD-MOSFET) structure with a built-in MOS channel diode. Further, its characteristics were analyzed using TCAD simulation. The DTMCD-MOSFET comprised active and dummy gates that were divided horizontally; the channel diode operated through the dummy gate and the p-base and N+ source regions at the bottom of the dummy gate. Because the bult-in channel diode was positioned at the bottom, the DTMCD-MOSEFT minimized static deterioration. Despite having a 5.2% higher specific on-resistance (Ron-sp) than a double-trench MOSFET (DT-MOSFET), the DTMCD-MOSFET exhibited a significantly superior body diode and switching properties. In comparison to the DT-MOSFET, its turn-on voltage (VF) and reverse recovery charge (Qrr) were decreased by 27.2 and 30.2%, respectively, and the parasitic gate-drain capacitance (Crss) was improved by 89.4%. Thus, compared with the DT-MOSFET, the total switching energy loss (Etot) was reduced by 41.4%.