CNTFET 8T SRAM cell performance with near-threshold power supply scaling

In this study, we present a Carbon Nanotube (CNT) FET based 8T SRAM cell and its performance in near threshold voltage region. Metallic CNTs (M-CNTs) grow alongside semiconductor CNTs in current synthesis process, but they can be removed using novel techniques. This in turn creates open circuit and degrades the performance and functionality of SRAM cells. In this paper we apply a removed metallic CNT tolerant approach. The near threshold performance of the 8T SRAM cells with the tolerant approach is simulated and optimized to obtain best performance under the supply voltage from 0.4V to 0.9V. An evaluation of energy delay product and SNM shows a favorable tradeoff for the 0.6V power supply. The energy savings for cells with 0.6V power supply are 56.5% and 10.0% for average and worst case, respectively, compared with 0.9V; on the other hand, it has about 58% longer max delay and 25.8% lower static noise margin. The average and worst case values of EDP for 0.6V is 34.0% and 27.8% lower than that of 0.9V, with only 0.09% more invalid cell.