Suppression of switching loss dependence on charge imbalance of superjunction MOSFET

Abstract

We discuss switching behavior of superjunction (SJ)-MOSFETs in terms of interaction between MOS gate structure and charge imbalance (CIB) of SJ structure. Resistive load switching behavior of SJ-MOSFET was analyzed by device simulation. CIB changes the gate voltage transient behavior between gate threshold voltage and gate plateau voltage via modification of the potential near the gate. We found key parameter which determines the effect of MOS structure and layout upon loss, and indicated robust MOS gate design and layout from the perspective of switching loss. Finally, we confirmed the conclusion by experiment.