An Intensive Study of Tree-Shaped JL-NSFET: Digital and Analog/RF Perspective
Sresta Valasa, Shubham Tayal, Laxman Raju Thoutam
Abstract
This manuscript for the first time presents the digital and analog/RF performance analysis for novel Tree-shaped Junctionless Nanosheet (NS) FET. An additional inter-bridge (IB) channel is added to the vertically stacked JL-NSFET to form a Tree-shaped structure. The Tree-shaped JL-NSFET is compared with the conventional JL-NSFET for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${L}_{g}$ </tex-math></inline-formula> = 16 nm, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${T}_{\text {NS}}$ </tex-math></inline-formula> = 5 nm, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{\text {NS}}$ </tex-math></inline-formula> = 18 nm, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{\text {IB}}$ </tex-math></inline-formula> = 2 nm, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${H}_{\text {IB}}$ </tex-math></inline-formula> = 6 nm. It is observed that ON-current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{ \mathrm{\scriptscriptstyle ON}}$ </tex-math></inline-formula> ) has been improved for Tree-shaped JL-NSFET by an amount of ~15.3% with a decent subthreshold swing of 61.5 mV/dec. The analog/RF performance of the Tree-shaped JL-NSFET has been improved satisfactorily as compared to the conventional JL-NSFET. Further to enhance the digital/analog RF performance the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{\text {IB}}$ </tex-math></inline-formula> is varied between 2–4 nm. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{ \mathrm{\scriptscriptstyle ON}}$ </tex-math></inline-formula> is increased by an amount of ~23.56% with the increase in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{\text {IB}}$ </tex-math></inline-formula> due to the increase in effective width. However, the same resulted in the degradation of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${A}_{V}$ </tex-math></inline-formula> , GFP, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${f}_{T}$ </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">${f}_{\text {MAX}}$ </tex-math></inline-formula> by an amount of ~1.72%, ~3.39%, ~4.46%, and ~8.39%, respectively, at 1-nA normalized drain current. Hence lower <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${W}_{\text {IB}}$ </tex-math></inline-formula> must be chosen for the improvement of analog/RF parameters. Furthermore, the effect of temperature (100–400 K) on Tree-shaped JL-NSFET is also investigated and the performance is best recorded at lower temperatures. At 1-nA normalized drain current, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${g}_{m}$ </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">${A}_{V}$ </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">${f}_{T}$ </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">${f}_{\text {MAX}}$ </tex-math></inline-formula> , and GFP are noticeably improved by an amount of ~68.6%, ~5.84%, ~65.02%, ~34.14%, and ~56.02%, respectively. Moreover, the effect of IB height ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${H}_{\text {IB}}$ </tex-math></inline-formula> ) is explored (6–14 nm) and it is inferred that <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${H}_{\text {IB}}$ </tex-math></inline-formula> should be optimized to get better digital and analog/RF performances according to the application areas.