Investigation on the short-circuit capability of 1200 V trench gate field-stop IGBTs

The short circuit failure mechanism of newly developed 1200 V/150 A trench gate field-stop IGBT has been investigated. The devices mainly fail after a few hundred microseconds of the short-circuit turn-off. It has been found that the leakage current due to extreme temperature rise in the backside layers results in thermal runaway during off-state. The device with improved backside layer achieved more than 15 /spl mu/s of short circuit capability while keeping the low on-state voltage drop of 1.55 V.