On the origin of frequency dependence of single-trap induced degradation in AC NBTI

The frequency dependence of the single-trap induced degradation (STID) are investigated both experimentally and theoretically, which is the key for the understanding of AC NBTI characteristics and temporal variations. Instead of the conventional 2-state trap model (2SM), the 4-state trap model (4SM) are studied through Monte-Carlo simulation in detail, which give a reasonable interpretation of the abnormal experimental results. A simple physical model is also proposed for the frequency dependence prediction, which agrees well with the simulation and experiments. This work is helpful for the evaluation of the impact of AC NBTI under different frequencies.