Investigations on current filamentation of IGBTs under undamped inductive switching conditions

Abstract

We have investigated current filamentation of IGBTs occurring under UIS (undamped inductive switching) conditions, by using electro-thermal device simulations. In this paper, we present that the formation of a current filament inevitably takes place even if the device active region include no weak spots. In addition, it is clarified that the current filament travels inside the active region with Joule self-heating, and the filament pinning due to parasitic bipolar action at the weak spot leads to lowering UIS capability.