Investigation on the static noise margin of 6T SRAM composed of 2D semiconductor MOSFETs

This work investigates the static noise margin (SNM) of 6T SRAM composed of 2D semiconductor MOSFETs. A analytical current-voltage model for 2D semiconductor MOSFETs is applied to analyze all transistors in a 6T SRAM. Simulation model and method are built for basic 6T SRAM structure and that with S/D contact resistance. Effects on SNM of contact resistance and inefficient channel doping are studied, and the worst case of reduction in SNM due to threshold fluctuation is investigated. Results show that SNM decreases from 117mV to 87mV for S/D contact resistance increasing from 0 to 2000Ω, and SNM decreases from 117mV to 35mV for effective channel area doping density decreasing from 3.5 × 10¹¹cm^-2 to 3.5 × 10⁸cm^-2. Enlarging the nominal threshold of access transistors helps improve the maximum threshold voltage tolerance.