SIMULATION OF TRANSIENT SELF‐HEATING DURING POWER VDMOS TRANSISTOR TURN‐OFF

The transient thermal behaviour, based on a rigorous transient thermodynamic treatment, of a power VDMOS transistor during turn‐off is presented. The time variation of the interior lattice temperature within the device is calculated by self‐consistently solving the fully coupled Poisson's equation and transient electron continuity equation together with the transient heat flow equation. The simulation takes account of temperature dependent heat conduction and capacity and includes thermoelectric currents due to temperature gradient. To make the transient thermal simulation more robust, a new analytical expression for heat capacity is used.