Influence of inhomogeneous current distribution on the thermal SOA of integrated DMOS transistors

The forward bias safe operating area (FBSOA) of integrated VDMOS transistors in a 60 V smart power technology is studied under single stress. It is shown that it is necessary to consider the operating point dependent current distribution across the device area to model the thermal limits of larger devices (∼mm²). The transient temperature profile and the resulting electrical characteristics can be modeled using electro-thermal simulations, taking correctly the distributed nature of the device, and thus of the non-uniform power density into account.