Record Performance in GAA 2D NMOS and PMOS Using Monolayer MoS2 and WSe2 with Scaled Contact and Gate Length

Abstract

2D transition metal dichalcogenides are promising candidates as channel material choice in ultimately scaled CMOS. We report record performance in GAA 2D NMOS transistors using monolayer MoS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> with three advances: scaled gate length (Lg) down to 25nm, scaled contact length (Lc) of 38nm, and the elimination of the low-k “inter-layer” in the gate stack enabling the first fully high-k GAA 2D device. We achieve 90% yield for scaled Lg <50nm with SS of 86mV/dec and on-currents reaching <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$485\mu \mathrm{A}/\mu \mathrm{m}$</tex>. Drive currents of 342μA/μm are maintained after contact length scaling down to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\sim 40\text{nm}$</tex>. We report the first BTI on any 2D GAA device and deposited high-k interface, showing <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{HfO}_{2}$</tex> may be advantageous for 2D reliability compared to typical <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{Al}_{2}\mathrm{O}_{3}$</tex> inter-layers. Signs of short-channel effects are observed at the shortest Lg, identifying EOT scaling as essential area of improvement. We also report record ION=92μA/μm in scaled Lg GAA PMOS transistors with monolayer WSe2.