Impact of Aging Phenomena on Soft Error Susceptibility

In this paper we address the issue of analyzing the effects of negative bias temperature instability (NBTI) on ICs´ soft error susceptibility. We show that NBTI reduces significantly the critical charge of nodes of both combinational and sequential circuits during their in-field operation. Furthermore, we prove that combinational circuits present a higher relative reduction of node critical charge than sequential ones. Therefore, as an IC ages, the soft-error susceptibility of its combinational parts will increase much more than that of its sequential parts. This poses new challenges to ICs´ soft error susceptibility modeling, mandating a time dependent modeling (in contrast to the static modeling broadly considered till now), and a diverse time dependent modeling for their combinational and sequential parts.