High-Performance Dual-Gated Single-Layer WS<sub>2</sub> MOSFETs With Bi Contacts
Lun Jin, Steven J. Koester
Abstract
The demonstration of high drive current in chemical vapor deposition (CVD)-grown single-layer (1L) WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> metal-oxide-semiconductor field-effect transistors (MOSFETs) is reported. The best device with gate length, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\vphantom {_{\int }} {L}_{G}$ </tex-math></inline-formula> , of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.32 ~\mu \text{m}$ </tex-math></inline-formula> displayed ON/OFF ratio as high as 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> and saturated 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">${I}_{D(SAT)}$ </tex-math></inline-formula> , of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$245 ~\mu \text{A}/\mu \text{m}$ </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">$340 ~\mu \text{A}/\mu \text{m}$ </tex-math></inline-formula> ) at room temperature (78 K). This device had <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${L}_{G} \times {I}_{D(SAT)} = 78 ~\mu \text{A}$ </tex-math></inline-formula> , providing strong evidence of the potential of CVD-grown WS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> for realizing high-performance transistors.