A 14 nm FinFET 128 Mb SRAM With V<formula formulatype="inline"> <tex Notation="TeX">MIN</tex></formula> Enhancement Techniques for Low-Power Applications

Two 128 Mb dual-power-supply SRAM chips are fabricated in a 14 nm FinFET technology. A 0.064 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">μ</tex> </formula> m <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">²</tex> </formula> and a 0.080 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">μ</tex> </formula> m <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">²</tex> </formula> 6T SRAM bitcells are designed for high-density (HD) and high-performance (HP) applications. To improve <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">V_ MIN</tex></formula> of the high-density SRAM, a negative bitline scheme (NBL) is adopted as a write-assist technique. Then, the disturbance-noise reduction (DNR) scheme is proposed as a read-assist circuit to improve the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">V_ MIN</tex></formula> of the high-performance SRAM. The 128 Mb 6T-HD SRAM test-chip is fully demonstrated featuring 0.50 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">V_ MIN</tex></formula> with 200 mV improvement by NBL, and 0.47 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">V_ MIN</tex></formula> for the 128 Mb 6T-HP with 40 mV improvement by the DNR. Improved <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">V_ MIN</tex></formula> reduces 45.4% and 12.2% power-consumption of the SRAM macro with the help of each assist circuit, respectively.