On the Extreme Scaling of Transistors with Monolayer MOS2 Channel
Wen-Chia Wu, Terry Y.T. Hung, D. Mahaveer Sathaiya, Edward Chen, Chen-Feng Hsu, Walker Yun, Hsiang-Chi Hu, Bo-Heng Liu, T.Y. Lee, Chi‐Chung Kei, Wen‐Hao Chang, Jin Cai, Wallace Jeff, Chung-Cheng Wu, H.‐S. Philip Wong, Chao-Hsin Chien, Chao-Ching Cheng, Iuliana Radu
Abstract
2D transition metal dichalcogenides (TMDs) show promise for transistor scaling, but their on-scale performance had not been proven yet. This work demonstrates contact length (Lc) scaling while holding a low contact resistance (R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</inf>) down to 11 nm. Channel length <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathrm{L}_{\text{CH}})$</tex> scaling shows I<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</inf> can increase down to at least 12 nm with low Rc. The very scaled <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathrm{L}_{\text{CH }}=19$</tex> nm and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{L}_{\mathrm{C}}=12$</tex> nm) Mos2 transistor with Sb-based metal contact has current density of ~1130 μA/μm at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{V}_{\text{DS}}$</tex>= 1 V, and a low <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{R}_{C}$</tex> of ~ 190 Ω.μm. These scaled transistors, processed within a back-end-of-line (BEOL) thermal budget, do not exhibit subthreshold swing (S.S.) degradation or observable drain-induced barrier lowering (DIBL) down to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{L}_{\text{CH}}=12\text{nm}$</tex>.