Thermal instabilities in high current power MOS devices: experimental evidence, electro-thermal simulations and analytical modeling

Abstract

The phenomenon of the thermal instability presented by some high current power MOS has been intensively investigated, both by experimental means and by numerical simulations. An analytical expression for the positive temperature coefficient of the Drain current has been developed and a model for the thermal instability in transient operation has been proposed. The results explain the main causes of the thermal instability and give some rules to evaluate the possible failure occurrence for a given device.