CMOS COMPATIBLE SHORTED ANODE AUXILIARY CATHODE LATERAL INSULATED GATE BIPOLAR-TRANSISTORS

The performance of CMOS compatible shorted anode auxiliary cathode lat eral insulated gate bipolar transistors (SA-ACLIGBT), fabricated using a standard 2.5 mum digital CMOS compatible high voltage integrated ci rcuit 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 in these devices. These devices show a latchup -free, current saturation behavior when compared to their equivalent s horted anode LIGBT's. Measured high voltage turnoff characteristics of the SA-ACLIGBT are superior to those of the conventional SA-LIGBT. Th ese results confirm that by placing 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 rol e in preventing the triggering of the parasitic thyristor; it also pla ys an important role in extracting minority carriers during the turnof f transient.