Active trench barrier RC-IGBT with pinch-off and carrier accumulation effects

A Reverse Conduction Insulated Gate Bipolar Transistor (RC-IGBT) featuring an Active Trench Barrier (ATB) based on Super-Junction (SJ) technology is proposed and investigated. The double-trench gates are designed at the N-pillar and P-pillar of the SJ drift. Consequently, a p-type ATB located between the two trench gates is formed. The ATB working mechanism is controlled and modulated by the Gate Voltage ( V GE ) of the double-trench gates. In the forward conduction state, the ATB channel is depleted and automatically pinched off by the positive V GE . Thus, the barrier potential of the ATB is remarkably improved. Additionally, holes accumulate underneath the ATB and maintain high conductivity modulation of the SJ drift region. Thus, the low on-state voltage drop ( V ON ) is obtained. In the reverse conduction state, the ATB pinch-off effect automatically fades away with the grounded V GE . In addition, the ATB, P-pillar, and N + act as the anode, drift, and cathode of the Free-Wheeling Diode (FWD), respectively. Electrons are blocked and accumulated by the trench gates. Thus, the hole injection is enhanced and the reverse conduction voltage ( V R ) is reduced. In the turn-off state, excessive holes can be effectively extracted by the extra ATB channel, and the turn-off loss ( E OFF ) is remarkably decreased. As a result, the trade-off relationship between V ON and E OFF can be significantly improved, which achieves the best comprehensive property when compared with the conventional RC-IGBT and SJ-IGBT.