Semi-superjunction IGBT with a relatively high-resistance p-top region for low on-state and turn-off losses

Abstract A semi-superjunction (semi-SJ) IGBT with a relatively high-resistance p-top region is proposed and studied by simulations. The p-top region is able to suppress the collection of holes by the p-pillar to enhance the carrier storage effect in the on-state, which helps to obtain excellent trade-off between turn-off loss (Eoff) and on-state voltage drop (VCE(sat)). An n-drift layer is used to sustain a part of the applied voltage, so the thickness of the n/p-pillars can be decreased to reduce manufacturing cost and difficulties of superjunction (SJ). Compared to the conventional semi-SJ IGBT, the proposed semi-SJ IGBT has a nearly same Eoff and a 0.3–0.6 V lower VCE(sat) under pillar doping concentration Npillar = 4–8 × 1015 cm−3. Besides, it is interesting to find that the optimum design for minimum Eoff under the same VCE(sat) is not obtained in the full SJ case (i.e., the case without the n-drift layer), and minimum values of Eoff are very close under Npillar = 4–8 × 1015 cm−3.