CMOS compatible shorted anode auxiliary cathode lateral insulated gate bipolar transistors

The performance of CMOS-compatible, shorted-anode, auxiliary-cathode lateral insulated gate bipolar transistors (SA-ACLIGBT), fabricated using a standard 2.5-μm high-voltage integrated circuit process, is investigated. Typical on-state current densities of more than 240 A/cm² at a gate voltage of 10 V and a forward voltage of 5 V have been obtained. These devices show a latchup-free, current saturation behavior when compared to equivalent shorted-anode LIGBTs. Measured high-voltage turnoff characteristics of the SA-ACLIGBT are superior to those of the conventional SA-LIGBT. These results confirm that by including an auxiliary cathode and extending a p ⁺ buried layer from under the p well into the drift region of the SA-LIGBT structure, the holes flowing into the p well can be diverted to improve device performance. The auxiliary cathode plays a vital role in preventing the triggering of the parasitic thyristor; it also plays an important role in extracting minority carriers during the turnoff transient