Superjunction MOSFET with Trench Schottky Contact and Embedded High-k Insulator for Excellent Reverse Recovery

A new superjunction MOSFET (SJ-MOSFET) with trench Schottky contact and embedded high-k insulator is proposed and investigated by TCAD simulations. In the reverse conduction state, the trench Schottky contact can easily collect electrons. So the hole injection efficiency of the body diode can be lowered to reduce the reverse recovery charge (Qrr). In addition, the high-k insulator is embedded in the p-pillar, which can increase the p-pillar resistance during reverse recovery so as to reduce the current recovery rate (dir/dt) from the peak reverse current (Irrm) to zero. Simulation results show that, the Qrr and dir/dt of the proposed SJ-MOSFET can be reduced by 46% and 71% respectively, compared with the conventional SJ-MOSFET.