Degradations characterization for IGBTs operating above the 125/spl deg/C MIL temperature in AC converters

IGBTs (insulated gate bipolar transistor) are formed of smaller die sizes compared to transistors usually used in AC converters for the same power handling. The operating junction temperature of IGBTs is easily above the military limit of 125/spl deg/C in this case. The IGBT was placed at a temperature of 155/spl deg/C for an hour. The component was characterized before and after stress. Effects of stress were analyzed. Holes at the oxide-semiconductor interface compensate the effect of charges in the oxide. A drop in the channel mobility /spl mu/ was induced, as well as a relatively lower decrease of diffusion mechanism with respect to the recombination. The life duration of the minority carriers in the N/sup -/ layer (/spl tau/) has decreased associated to internal degradations such as network damage through the displacement of its atoms corresponding to the creation of recombining centers in volume in the base of the bipolar transistor internal to the IGBT.