Experimental Demonstration of a 650-V Superjunction MOSFET With Dual Schottky Contacts for Fast Reverse Recovery

In this article, we demonstrate the experimental results of a 650-V superjunction MOSFET (SJ-MOSFET) featuring dual Schottky contacts at the source side to reduce the reverse recovery charge ( $\textit{Q}_{\text{rr}}\text{)}$ of its body diode. The n-type Schottky contact suppresses the operation of the p-n junction, and the p-type Schottky contact lowers the hole injection efficiency further. Both of them reduce $\textit{Q}_{\text{rr}}$ . According to the experimental results, $\textit{Q}_{\text{rr}}$ of the proposed SJ-MOSFET (1.4 $\mu$ C) is 20.5% of that of the conventional device (6.8 $\mu$ C) and 38.9% of that of the device with only n-type Schottky contact (3.6 $\mu$ C). The forward voltage drop of its body diode is 0.91 V, which is 0.07 V higher than that of the conventional device and 0.09 V higher than that of the device with only n-type Schottky contact. These characteristics make it be suitable for high-speed switching applications.