An SNM estimation and optimization model for ULP sub-45nm CMOS SRAM in the presence of variability

This paper presents a universal optimization model for Static Noise Margin (SNM) of Ultra Low Power (ULP) CMOS SRAMs in the presence of statistical variations. Distributions of retention and read SNM derived analytically, are analyzed as a function of the threshold voltages of the N and PMOS devices. The proposed model implemented in Matlab is applied to optimize yield by maximizing the μ/6σ of SNM in the presence of local statistical V
_T
variation of 3σ.