Superjunction MOSFET with a Trench Contact and Embedded SiO2 Insulator for Excellent Reverse Recovery

Inhalt:
A new superjunction MOSFET (SJ-MOSFET) with a trench contact and embedded SiO2 insulator (ESO) is proposed and investigated by TCAD simulations. At the reverse conduction state, since electrons in the n-pillar can be easily collected by the trench contact, the hole injection efficiency of the body diode can be lowered to reduce the reverse recovery charge (Qrr). In addition, the SiO2 insulator is embedded in the p-piller, which can increase the resistance of the hole extraction path 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, compared with the conventional SJ-MOSFET, Qrr an dir/dt of the proposed SJ-MOSFET can be reduced by 44% an82%, respectively.