Development of high switching speed IGBT device using proton irradiation technology

High switching speed IGBT device technology has been developed employing proton irradiation. Proton irradiation with various doses of energies have been carried out into IGBT device as a wafer state. The electrical properties, such as forward current-voltage characteristics, reverse breakdown voltage, turn-off transient characteristics were analyzed and compared with those of electron irradiated device which has been the conventional method for switching speed improvement. The saturated collector voltage of proton irradiated device which represents the on-state resistance was 1.9 V, that of electron device was 2.0 V, 1.3 V for un-irradiated device. The breakdown voltage of original device was 750 V, which was slightly reduced to 730 V after proton irradiation and that of electron irradiated device was 690 V. The turn-of delay time of original device was about 6 micro seconds. After proton irradiation the turn-off delay time was greatly enhanced to 170 nano seconds, coming 280 nsec for electron irradiated device. In summary, the high switching speed IGBT has been fabricated using proton irradiation technology. The turn-off delay time was reduced to about 60% of conventional electron irradiated device with similar forward on-state voltage and better breakdown voltage