Gate Delay Variability due to Random Telegraph Noise

Abstract

Stochastic timing variations are a major concern in nanometric CMOS logic gates. Addressing the time-zero fluctuations due to variability of physical dimensions and doping profiles, which remain static over time, as well as the time-dependent fluctuations, such as Random Telegraph Noise (RTN), is, therefore, imperative for proper circuit design. In this work, we study how the observation window impacts gate delay variability due to RTN, illustrating how it affects the observed variance of the gate delay taken over time. Our study indicates that the relation between propagation delay and trap time constant is a proper measure (benchmark) to evaluate the time constant of the fastest trap that induces time dependent variability. And that observation duration (measurement duration) is a proper measure (benchmark) to evaluate the time constant of the slowest trap that induces time dependent variability.