A study on the short-circuit capability of field-stop IGBTs

The short-circuit failure mechanism of 1200 V trench gate field-stop insulated gate bipolar transistor (IGBT) has been investigated in this paper. Experimental testing shows that most of the devices failed during the blocking state after a few hundred microseconds of the short-circuit turn-off condition. This unusual failure mode was analyzed both with experimental and numerical investigation. It has been determined that due to significantly large leakage current, thermal run-away can occur causing device failure after short circuit turn-off. Due to the smaller heat capacity of the FS-IGBT structure, the device temperature after the turn-off becomes so high that the local heating produced by the high temperature leakage current results in the thermal run-away.