Highly robust nanoscale planar double-gate MOSFET device and SRAM cell immune to gate-misalignment and process variations

Abstract

Gate misalignment and process variations are important challenges in sub-20 nm gate length planar double-gate (DG) MOSFET devices. For the first time, we demonstrate a misalignment- and process variations-aware device optimization strategy for a DG-MOSFET. Using underlaps and high-kappa offset-spacers, we show that the robustness of the device to gate misalignment and process variations can be improved. A standard 6T-SRAM cell designed using the optimized devices shows better read and hold static noise margins, and lower variations in SNM and leakage power compared to a conventional DG-MOSFET.