An improved NMOS AC hot-carrier lifetime prediction algorithm based on the dominant degradation asymptote

Abstract

This study presents a new algorithm for improved prediction of AC hot-carrier lifetime. It is based on identifying and projecting the dominant degradation asymptote. The algorithm accounts for the stress-bias dependence of the hot-carrier degradation rate and the nonlinearity of the degradation time-dependence. Detailed model parameter extraction and lifetime prediction procedures are explained, and applications of the new algorithm demonstrated. Significant differences in the predicted AC lifetimes are found between the existing and the new algorithms over a wide range of CMOS inverter design parameters, such as the input ramp rate and the load capacitance.