Experimental study on the variation of NBTI degradation in nano-scaled high-K/metal-gate PFETs

In this paper, the 2-D distribution of the power law time exponent (n) in NBTI degradation is experimentally studied in nanoscale high-K/metal-gate devices for the first time. By adopting the recently-proposed statistical trap-response (STR) technique, the distribution of n due to both device-to-device variation (DDV) and cycle-to-cycle variation (CCV) is taken into account. Large error (up to 80%) can be found without considering DDV or CCV in the evaluation of n. Moreover, the mean value and the variation of n distribution are further extracted and discussed with considering different extraction methods for accurate prediction of NBTI degradation in nanoscale devices and circuits.