Internal dynamics of IGBT during short circuit switching

This paper reports the internal dynamics of IGBT under short circuit switching conditions. Short circuit performance of IGBTs has been studied in detail with the aid of extensive measurements and numerical simulations. An advanced two-dimensional mixed device and circuit simulator has been employed to examine IGBT behaviour under short circuit stress. The self-heating mechanism is incorporated by self-consistently solving heat generation and diffusion equations with semiconductor charge balance and transport equations. A latch-up free punch-through IGBT has been examined. It is shown that hot-spot generation due to current crowding and impact ionization are the causes of breakdown of an IGBT under short circuit switching. Use of a wider gate is likely to improve the ruggedness of the device.