NBTI and irradiation related degradation mechanisms in power VDMOS transistors

In this paper it is shown that NBT stress effects in previously irradiated devices are strongly dependent on the total dose received. Namely, in the case of low-dose irradiation the subsequent NBT stress seems to lead to further device degradation. On the other hand, in the case of devices previously irradiated to higher doses, NBT stress seems to have positive role as it practically anneals a part of radiation-induced degradation. The total dose received at which NBT stress almost completely anneals radiation-induced degradation is determined to be around 60 Gy.