Switching Noise-Loss Trade-Off Improvement of SJ-IGBTs

Design of trench gate and p-column position in Superjunction (SJ)-IGBTs are discussed to improve the tradeoff characteristics between surge voltage/current and turn-off/on losses. Power electronics systems require not only low power loss but also low EMI noise for high cost performance by system downsizing. Although SJ-IGBTs are attractive for low loss operation due to thin drift layer and fast removal of the excess carriers through the p- and n-columns at the turnoff operation, the switching trade-off characteristics of SJIGBTs compared with the conventional IGBT and the improvement design have not been discussed sufficiently. This paper shows better switching trade-off compared with a conventional IGBT can be obtained by the trench gate and p-column designs due to management of the gate capacitance and hole current flow, because negative gate capacitance influences on not only turn-on switching but also turn-off switching.