Simulation of High-Voltage Injection-Enhanced 4H-SiC N-Channel IGBTs with Forward Drop Approaching that of a PiN Junction Rectifier

Abstract

For SiC devices capable of blocking very high voltages (>4kV), it becomes imperative to use bipolar devices because of unacceptably large on-state losses of unipolar devices. The IGBT offers the potential for high current density operation and ease of turn off using a MOS gate structure. In this work, 15kV 4H-SiC n-channel UMOS PT (Punch Through) IGBTs with injection enhancement effect near the top emitter and transparent pemitter structure at the collector have been demonstrated to have a forward drop approaching that of a PiN junction rectifier. With proper design, a PiN-like carrier distribution in the drift region can be achieved, which allows a better trade-off between collector-emitter saturation voltage (VCE(sat)) and turn-off loss (Eoff) than conventional SiC UMOS IGBTs.