Low noise superjunction MOSFET with integrated snubber structure

Abstract

Novel superjunction (SJ)-MOSFET structure with distributed internal snubber area is proposed. RC network composed by gate electrode, oxide and P-type pillar provides frequency-dependent capacitive coupling between each terminal. The snubber area acts as gate-drain capacitance (Cgd) only at high-frequency band. Switching noise generated during turn-off transient is absorbed by the snubber without increasing switching loss. We verified the concept by simulation and experiments, and confirmed better trade-off between EMI (Electromagnetic interference) and efficiency.