Analyzing static noise margin for sub-threshold SRAM in 65nm CMOS

Abstract

This paper evaluates the static noise margin (SNM) of 6T SRAM bitcells operating in sub-threshold. We analyze the dependence of SNM during both hold and read modes on supply voltage, temperature, transistor sizes, local transistor mismatch due to random doping variation, and global process variation in a commercial 65nm technology. We analyze the statistical distribution of SNM with process variation and provide a model for the tail of the PDF that dominates SNM failures.