Source electrode evolution of a low voltage power MOSFET under avalanche cycling

This paper presents the impact of high current repetitive avalanche pulses on a low voltage vertical power MOSFET at high temperature. Measurements show that RDSon decreases with the number of avalanche cycles whereas other electrical parameters stay constant. A simple model proposed in this paper shows that RDSon measurements are linked to MOSFET source electrode evolution. Also once source electrode has aged standard RDSon measurements at high current using force and sense are no more representative of silicon on resistance.