Numerical simulation of DB-NBTI degradation introduced by different length of interface charges

Abstract

To explore the influence of the interface charges on the threshold voltage of pMOSFET, we present a novel device model in this paper. By dividing the gate oxide layer into several regions, and setting different interface charges in different regions, the relationship between the interface charges' length and the threshold voltage is well simulated by using 2D numerical simulation, in which the conditions of drain biasing and interface charges' concentration are considered. At the same time, the mechanism of threshold voltage variation is also investigated by comparing the surface potentials of various models. The proposed work can promote the research on Drain Bias-Negative Bias Temperature Instability (DB-NBTI) effect.