NBTI related degradation and lifetime estimation in p-channel power VDMOSFETs under the static and pulsed NBT stress conditions

The effects of static and pulsed NBT stressing on threshold voltage in p-channel power VDMOSFETs are analysed, and the results are compared in terms of the effects on device lifetime. The results obtained by both 1/V-G and 1/T models, which are used for extrapolation to normal operation voltages and temperatures, respectively, indicate the device lifetime could be much longer under the pulsed stress conditions than under the static ones. It is also shown that lifetime tends to increase with decreasing the duty cycle of pulsed stress voltage applied. (C) 2011 Elsevier Ltd. All rights reserved.