UIS Analysis and Characterization of the SONOS Gate Power MOSFET

In this paper, unclamped inductive switching (UIS) performance of the novel silicon-oxide-nitride-oxide-silicon (SONOS) gate power MOSFET (SG-MOSFET) is analyzed. The avalanche energy absorption of the SG-MOSFET at UIS is 5.2 times that of the conventional power MOSFET. Analysis shows that the improvement is due to the heavily doped p-body used in the device. Moreover, the influence of the structural parameters on the UIS performance of the device is experimentally characterized. Measurement results show that the UIS performance is not sensitive to the p
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contact width and slightly degrades with a larger gate length. Furthermore, the results show that it is promising to further improve the UIS performance of the device by using a more efficient charge trapping material in the gate dielectric to allow further increase in the p-body doping concentration.