Numerical simulation of static noise margin for a six-transistor static random access memory cell with 32nm fin-typed field effect transistors

Abstract

We in this paper for the first time explore the static noise margin (SNM) of a six-transistor (6T) static random access memory (SRAM) cell with nanoscale silicon-on-insulator (SOI) fin-typed field effect transistors (FinFETs). The SNM is calculated with respect to the supply voltage, operating temperature, and cell ratio by performing a three-dimensional mixed-mode simulation. To include the quantum mechanical effect, the density-gradient equation is simultaneously solved in the coupled device and circuit equations. The standard deviation (sigma-(S N M)) of SNM versus device's channel length is computed, based upon the design of experiment and response surface methodology. Compared with the result of SNM for SRAM with 32nm planar metal-oxide-semiconductor field effect transistors, SRAM with SOI FinFETs quantitatively exhibits higher SNM and lower sigma-(S N M). Improvement of characteristics resulting from good channel controllability implies that SRAM cells fabricated with FinFETs continuously maintains cell stability in sub-32nm technology nodes.