Papers by Keyword: IEGT

Abstract: The impact of device concepts of Si insulated gate bipolar transistors (IGBTs) such as injection-enhanced IGBT (IEGT), high-conductivity IGBT (HiGT), and Si-limit IGBT on the performance of SiC IGBTs is examined. We first show that the forward characteristics of the original type of planer SiC IGBTs are much worse than those of SiC PiN diodes, even if the carrier lifetime is improved. Next, we show that the forward characteristics of SiC IEGTs and SiC HiGTs are comparable to those of SiC PiN diodes. Thus, device concepts of Si IGBTs are effective in improving the device performance of SiC IGBTs. Finally, it is shown that a SiC-limit IGBT can be realized when the mesa width is less than 0.5 μm.

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.