The Drain Bias Modulation Effect of Random Telegraph Noise in Gate-All-Around FETs for Cryogenic Applications
Yichao Sun, Peng Lü, Yue Ma, Chenrui Zhang, Zhengsheng Han, Bo Li
Abstract
In this letter, the random telegraph noise (RTN) in 25-nm-physical-channel-length gate-all-around field effect transistors (GAA FETs) are thoroughly investigated. Electrical characterizations at cryogenic condition (10 K) indicate that the drain bias ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{{\textit {DS}}}$ </tex-math></inline-formula> ), which has little impact on the RTN in long-channel transistors, can strongly affect that in ultra-scaled devices. An increase of 0.15 V in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{{\textit {DS}}}$ </tex-math></inline-formula> led to a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 10\times $ </tex-math></inline-formula> enlargement of the statistical high-state time constant ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\tau _{c}$ </tex-math></inline-formula> ) together with a ~20x reduction of the statistical low-state time constant ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\tau _{e}$ </tex-math></inline-formula> ), which could be attributed to the more pronounced drain fringing field in short-channel devices. More significantly, because the drain fringing field counteracts the gate electric field, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta ~{V}_{{\textit {DS}}}$ </tex-math></inline-formula> -induced <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\tau _{c}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\tau _{e}$ </tex-math></inline-formula> variation trends are contrary to those caused by the gate bias. An analytical model, which captures the non-uniform electric field profile in short-channel devices, has been developed for quantitative RTN analysis. Single-level traps close to the channel/drain junction are found to be the major contributor to the RTN, providing guidance for future process optimization.