CVD Graphene Contacts for Lateral Heterostructure MoS${_2}$ Field Effect Transistors

TL;DR

This paper demonstrates scalable CVD graphene contacts for MoS2 transistors, achieving low contact resistance and high on/off ratios, with a theoretical model suggesting further miniaturization and performance improvements for future logic circuits.

Contribution

It introduces a novel fabrication of lateral heterostructure transistors with CVD graphene contacts and provides a theoretical model for further scaling and optimization.

Findings

Low contact resistance of about 9 kΩμm achieved

High on/off current ratio of 10^8 demonstrated

Theoretical model indicates potential for further miniaturization

Abstract

Intensive research is carried out on two-dimensional materials, in particular molybdenum disulfide, towards high-performance transistors for integrated circuits. Fabricating transistors with ohmic contacts is challenging due to the high Schottky barrier that severely limits the transistors' performance. Graphene-based heterostructures can be used in addition or as a substitute for unsuitable metals. We present lateral heterostructure transistors made of scalable chemical vapor-deposited molybdenum disulfide and chemical vapor-deposited graphene with low contact resistances of about 9 k${\Omega}$${\mu}$m and high on/off current ratios of 10${^8}$. We also present a theoretical model calibrated on our experiments showing further potential for scaling transistors and contact areas into the few nanometers range and the possibility of a strong performance enhancement by means of layer optimizations that would make transistors promising for use in future logic circuits.