Modeling of the Subthreshold Swing in Cryogenic MOSFET With the Combination of Gaussian Band Tail and Gaussian Interface State
Xinyi Zhang, Zhicheng Wu, Jianhui Bu, Bo Li, Zhengsheng Han
Abstract
To quantitatively describe the inflection and the recently observed protrusion phenomenon in the subthreshold region at cryogenic temperature, this study presents a novel model featuring a Gaussian-distributed band tail, combining the Gaussian interface state positioned away from the energy band. The Gaussian band tail can capture the inflection phenomenon of low-temperature subthreshold swing (SS), and the introduction of the interface state in the forbidden band enables accurate modeling of the SS protrusion. The proposed model can favorably describe <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\text {DS}}$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {GS}}$ </tex-math></inline-formula> , SS– <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\text {DS}}$ </tex-math></inline-formula> , and SS– <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${T}$ </tex-math></inline-formula> spanning from 10 to 300 K of the commercial 0.35- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> bulk n/p- MOSFET and 14-nm n-FinFET technology, potentially enabling a unified method of capturing the SS of a MOSFET at the cryogenic temperature.