Method to extract parameters of power law for nano-scale SiON pMOSFETs under negative bias temperature instability

This paper proposes a fast and accurate method to extract parameters of the power law for nano-scale SiON pMOSFETs under negative bias temperature instability (NBTI), which is useful for an accurate estimation of NBTI lifetime. Experimental results show that accurate extraction of the time exponent n of the power law was obstructed by either fast trapping of minority carriers or damage recovery during measurement of threshold voltage V-th. These obstructing effects were eliminated using Delta V(th)s obtained from fast and slow measurement-stress-measurement (MSM) procedures. The experimental SiON pMOSFETs had n approximate to 1/4, an activation energy E-alpha = 0.04 eV for the fast recoverable degradation, and E-alpha = 0.2 eV for the slow permanent degradation. Based on these experimental observations, a method to estimate NBTI lifetime is proposed.