Probabilistic defect occupancy model for NBTI

Abstract

A new Negative Bias Temperature Instability (NBTI) model based on the probability of charge/discharge of defects in devices is presented. The model correctly describes the main experimental NBTI features, such as the threshold voltage shift (ΔVT) evolution under DC or AC stresses, its frequency and duty cycle dependence and the statistical ΔVT distribution in small transistors. Finally, the model is used to explain the dependence of NBTI degradation on the stress/relaxation times, frequency and duty cycle in terms of defect occupancy. © 2011 IEEE.