SiC Double-Trench MOSFETs With Embedded MOS-Channel Diode

Abstract

A novel SiC double-trench MOSFET (DT-MOS) with embedded MOS-channel diode is proposed and investigated via TCAD simulations in this article. The parasitic body diode is free from activation when the device serves as a freewheeling diode, thus completely eliminating the bipolar degradation. Moreover, the proposed MOSFET features superior dynamic characteristics. The gate charge ( ${Q}_{\text {G}}$ ) and gate-to-drain charge ( ${Q}_{\text {GD}}$ ) are reduced by a factor of ~1.8 and ~3.9, respectively, when compared to the conventional state-of-the-art SiC DT-MOS. Combined with the slightly increased ON-resistance ( ${R}_{ \mathrm{\scriptscriptstyle ON}}$ ), remarkably improved figures of merit ( ${R}_{ \mathrm{\scriptscriptstyle ON}} \times {Q}_{\text {G}}$ and ${R}_{ \mathrm{\scriptscriptstyle ON}}\times {Q}_{\text {GD}}$ are reduced by a factor of ~1.7 and ~3.7, respectively) are obtained in the proposed structure. When working as a switching device under 200 kHz, the proposed MOSFET could save nearly 64% of the total power losses, making it more conductive to high-frequency applications. In addition, the influence of parameters variation on the device performance is discussed as well.