Simulation Study on Dual Gate Control of Surface Buffer Insulated Gate Bipolar Transistor for High Switching Controllability

A new device design in trench-gate insulated gate bipolar transistor (IGBT) with dual gate control is proposed for high switching controllability with low loss operation. Injection enhancement effect is effective to obtain low power loss operation of IGBTs. However, excess drift carriers limit turn-off dV/dt, and turn-on dI/dt, and the switching controllability by the external gate resistance is degraded. Surface buffer (SB) IGBT with dual gate control is effective to improve the switching controllability, because the hole current can be modulated effectively by the p-MOS control. TCAD simulation results show the SB-IGBT type-II with dual gate control is the best choice for good turn-off and turn-on switching performances.