Superjunction MOSFET with a trench contact on partly relatively lightly doped P-pillar for excellent reverse recovery

A superjunction metal-oxide-semiconductor field-effect transistor (SJ-MOSFET) with a trench contact on partly relatively lightly doped p-pillar is proposed and investigated by TCAD simulations. At 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 (Q (rr)). Besides, the partly relatively lightly doped p-pillar increases the resistance of the hole extraction path so as to increase softness. Simulation results show that the proposed SJ-MOSFET can obtain a 46% lower Q (rr) than the conventional SJ-MOSFET and significantly suppress reverse recovery oscillations.