Quasi-1-Dimensional Dual-Gate MoS₂ Field-Effect Transistors with 50 nm Channel Length

Abstract

Quasi-1-dimensional dual-gate MoS 2 field-effect transistors (FETs) are demonstrated with channels composed of an array of nanospike source/drain electrodes. This geometry creates an effect of electric field tailoring and can laterally confine the conducting channel into charge nanoribbons. Due to effective lateral charge confinement below threshold, MoS 2 transistors with 50 nm channel length show greatly improved gate control when compared to conventional FETs with flat edge source/ drain electrodes of the same channel length. The device design also results in reduced drain induced barrier lowering and high intrinsic gain of 91 dB. Patterning of the source/drain electrodes into an array of nanospikes results in a reduction of charge injection perimeter without significant change in on-current and contact resistance. More importantly, these advantages are achieved without etching the semiconductor into nanoribbons, which typically results in enhanced scattering. The proposed device geometry is well suited for scaling down to channel lengths much smaller than 50 nm, especially when used with symmetric double gating or single gate FETs with high-k gate dielectrics.