Statistical Study of Deep Sub-Micron Dual-Gated Field-Effect Transistors on Monolayer CVD Molybdenum Disulfide Films

TL;DR

This study provides a comprehensive statistical analysis of dual-gated monolayer CVD MoS2 transistors, demonstrating record high drain current, contact resistance reduction, and mobility estimation across over 100 devices.

Contribution

It offers the first large-scale statistical characterization of CVD-grown monolayer MoS2 transistors, including device performance, contact resistance, and mobility metrics.

Findings

Record high drain current of 62.5 mA/mm achieved.

Intrinsic contact resistance can be reduced to 10 Ω·mm.

Average field-effect mobility of 13.0 cm²/Vs estimated.

Abstract

Monolayer Molybdenum Disulfide (MoS2) with a direct band gap of 1.8 eV is a promising two-dimensional material with a potential to surpass graphene in next generation nanoelectronic applications. In this letter, we synthesize monolayer MoS2 on Si/SiO2 substrate via chemical vapor deposition (CVD) method and comprehensively study the device performance based on dual-gated MoS2 field-effect transistors. Over 100 devices are studied to obtain a statistical description of device performance in CVD MoS2. We examine and scale down the channel length of the transistors to 100 nm and achieve record high drain current of 62.5 mA/mm in CVD monolayer MoS2 film ever reported. We further extract the intrinsic contact resistance of low work function metal Ti on monolayer CVD MoS2 with an expectation value of 175 {\Omega}.mm, which can be significantly decreased to 10 {\Omega}.mm by appropriate gating. Finally, field-effect mobilities ({\mu}FE) of the carriers at various channel lengths are obtained. By taking the impact of contact resistance into account, an average and maximum intrinsic {\mu}FE is estimated to be 13.0 and 21.6 cm2/Vs in monolayer CVD MoS2 films, respectively.