The universality of NBTI relaxation and its implications for modeling and characterization

As of date many NBTI models have been published which aim to successfully capture the essential physics [1-5]. As such, these models have mostly focused on the stress phase. The relaxation phase, on the other hand, has not received as much attention, possibly because of the contradictory results published so far. Particularly noteworthy are the very long relaxation tails of almost logarithmic nature [5-7], which cannot be successfully described by the reaction-diffusion model [7]. We argue that understanding the nature of the relaxation phase could hold the key to unraveling the underlying NBTI mechanism. In particular, we stipulate that the relaxation phase follows a universal relaxation 'law' [6,8-10], demonstrate the valuable consequences resulting therefrom, and use this universality to classify presently available NBTI models.