Low-Reverse Recovery Charge Superjunction MOSFET With a p-Type Schottky Body Diode

A novel low-reverse recovery charge superjunction MOSFET (SJ-MOSFET) with a p-type Schottky body diode is proposed in this letter. The device has a p-type Schottky contact on the p-pillar at the drain side. Electrons are prevented from injecting into the drain side by the p-type Schottky contact, and the total carrier concentration is greatly reduced. Compared with the conventional device, the proposed SJ-MOSFET has a lower reverse recovery charge and a larger soft factor. Simulated results show that the reverse recovery charge is reduced by 81.3% and 76.0% at 300 K and 400 K, respectively, with a metal work function of 4.5 eV. The optimized metal work function range is 4.3-4.6 eV.