Scaling of 32nm low power SRAM with high-K metal gate

Abstract

This paper describes SRAM scaling for 32 nm low power bulk technology, enabled by high-K metal gate process, down to 0.149 mum <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 0.124 mum <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . SRAM access stability and write margin are significantly improved through a 50% Vt mismatch reduction, thanks to HK-MG T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">inv</sub> scaling. Cell read current is increased by 70% over Poly-SiON process. Ultra dense cell process window is expanded with optimized contact process. A dual-ground write assist option can additionally enable ultra dense 0.124 mum <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> cell to meet low power application requirements.