Improved reverse recovery characteristics obtained in 4H-SiC double-trench superjunction MOSFET with an integrated p-type Schottky diode

摘要

A novel double-trench superjunction SiC metal-oxide-semiconductor field-effect transistor (MOSFET) with an integrated Schottky contact at the drain side is proposed in this study. Results indicate an improvement of 58% in reverse recovery current (I-rrm)/charge (Q(rr)) and 22% in the trench corner electric field (Eox-m) compared to the device without Schottky and without superjunction, respectively. This comparison became possible using mixed mode simulations in Sentaurus TCAD. While the improvement in electric field is due to incorporation of superjunction concept along the drift region, the improvement of reverse recovery is due to Schottky contact forming a barrier for the charge carriers. Using calibrated two-dimensional numerical simulations, the authors were able to demonstrate the influence of Schottky contact on reverse recovery current of the device. The superiority of the proposed device is presented by plotting the switching energy loss with respect to external gate resistance and temperature through non-isothermal simulations.