Contact Resistance Optimization in MoS${_2}$ Field-Effect Transistors through Reverse Sputtering-Induced Structural Modifications

TL;DR

This paper demonstrates that reverse sputtering modifies MoS2 interfaces to significantly reduce contact resistance, thereby enhancing the electrical performance of MoS2 FETs for potential use in advanced microelectronics.

Contribution

It introduces a novel application of reverse sputtering to induce conductive phases at MoS2 interfaces, reducing contact resistance in FETs.

Findings

Contact resistance reduced to less than 50%

Higher ON-state currents achieved

Reverse sputtering improves electrical performance

Abstract

Two-dimensional material (2DM)-based field-effect transistors (FETs), such as molybdenum disulfide (MoS${_2}$)-FETs, have gained significant attention for their potential for ultra-short channels, thereby extending Moore's law. However, MoS${_2}$-FETs are prone to the formation of Schottky barriers at the metal-MoS${_2}$ interface, resulting in high contact resistance (R${_c}$) and, consequently, reduced transistor currents in the ON-state. Our study explores the modification of MoS${_2}$ to induce the formation of conductive 1T-MoS${_2}$ at the metal-MoS${_2}$ interface via reverse sputtering. MoS${_2}$-FETs exposed to optimized reverse sputtering conditions in the contact area show R${_c}$ values reduced to less than 50% of their untreated counterparts. This reduction translates into improvements in other electrical characteristics, such as higher ON-state currents. Since reverse sputtering is a standard semiconductor process that enhances the electrical performance of MoS${_2}$-FETs, it has great potential for broader application scenarios in 2DM-based microelectronic devices and circuits.