Optimization of signal propagation performances in interconnects of the 45 nm node by exhaustive analysis of the technological parameters impact

Abstract

Due to the continuous shrink of technology dimensions, parasitic propagation delay time and crosstalk at interconnect levels increasingly affect overall circuit performances. New materials, processes and architectures are now required to improve BEOL performances. A rigorous high-frequency electromagnetic approach including the scattering effects on Cu line resistance was developed for coupled narrow interconnects to analyze the actual benefits of these innovations for different signal types covering application range from logic to I/O. Effects of advanced metallization (ALD thin barriers), low-k insulators (porous ULKs, low-k barriers), and innovative architectures (hybrid stacks, air gaps, self-aligned barriers) on signal propagation performance were quantified, resulting in an effective process selection for the 45 nm technological node and below.