Reproducible Monolayer MoS2 Devices Free of Resist Contamination by Gold Mask Lithography

TL;DR

This paper introduces a gold mask lithography technique that prevents surface contamination in monolayer MoS2 transistors, resulting in cleaner contacts and improved device performance compared to traditional methods.

Contribution

The study presents a novel gold mask lithography process that enables contamination-free fabrication of monolayer MoS2 devices, enhancing contact quality and device consistency.

Findings

Gold mask lithography reduces surface contamination.

Devices with gold contacts show Ohmic behavior.

Higher current variance in gold mask devices indicates process impact.

Abstract

Atomically thin MoS2 is a promising material for field-effect transistors (FETs) and electronic devices. However, traditional photolithographic processes introduce surface contamination to 2D materials, leading to poor electrical contacts when metals are deposited. In this work, we present a novel fabrication method using gold as a mask for patterning and etching, which protects 2D materials from contamination in the metal contact region. This technique enabled the fabrication of monolayer MoS2 transistors with clean gold contacts. Additionally, we achieved MoS2 devices with Ohmic contacts, mass-produced traditional lithography and gold mask lithography devices (100 of each), with the latter having a much higher current statistical variance than the former, which demonstrated the effectiveness of this method for contamination-free 2D transistors and potential applications in integrated circuits