Degradation of the low voltage power MOSFET electrical parameters during multipulse UIS test

Degradation of low voltage power MOSFET electrical parameters induced by high field and subsequent avalanche mechanisms during multipulse UIS test is presented. Unclamped inductive switching (UIS) condition represents the harsh circuit switching operation for evaluating the “ruggedness”. Introduction of multi-pulse UIS test better corresponds to a real industrial situation where devices have to sustain several consecutive stress pulses. Strong degradation of CV curves without degradation of IV curves was observed after 6 millions of stress pulses was observed. Deep levels generated by hot carriers during UIS were studied using DLTS measurement set-up. Obtained deep level traps were taken into account for the numerical simulations to verify measurements.