(015002)Enhanced Reverse Recovery Performance in Superjunction MOSFET with Reduced Hole-Barrier

摘要

High reverse recovery charge (Q_(RR)) and resultant high switching losses have become the main factors that constrain the performance and application area of superjunction MOSFET (SJ-MOSFET). To reduce Q_(RR), an SJ-MOSFET with reduced holebarrier is proposed and demonstrated. By introducing a Schottky contact on the bottom of the n-pillar at the drain side, the barrier for the hole carrier is dramatically reduced in the reverse conduction state. As a result, the hole carrier in the drift region is significantly reduced, which results in a low QRR and enhanced reverse recovery performance. Compared with the conventional SJMOSFET (Conv-SJ-MOSFET), the proposed device achieves 64.6% lower QRR with almost no sacrifice in other characteristics. The attenuated Q_(RR) accounts for a 19.6% ? 46.8% reduction in total power losses with operation frequency at 5 ? 200 kHz, demonstrating the great potential of the proposed SJ-MOSFET used in power conversion systems.