Experimental Characterization of Time-Dependent Variability in Ring Oscillators

Abstract

Reliability in CMOS-based integrated circuits has always been a critical concern. In today's ultra-scaled technologies, a time-varying kind of variability has raised that, on top of the well-known time-zero variability, threatens to shorten the lifetime of integrated circuits, both analog and digital. Effects like Bias Temperature Instability and Hot Carriers Injection need to be studied, characterized and modeled to include, and, thus, mitigate, their impact in the design of CMOS integrated circuits. This paper presents an array-based integrated circuit whose purpose is precisely that: to observe, quantify and characterize the impact of time-dependent variability effects in a specific kind of circuits: Ring Oscillators.