Contact resistance and interfacial engineering: Advances in high-performance 2D-TMD based devices

TL;DR

This paper reviews recent progress in reducing contact resistance in 2D-TMD devices by exploring interface engineering, hybrid contacts, and doping techniques to enhance device performance.

Contribution

It provides a comprehensive overview of mechanisms behind contact resistance and recent innovative strategies to overcome these challenges in 2D-TMD electronics.

Findings

Understanding of Fermi pinning effects at interfaces

Advances in van der Waals contact techniques

Effective doping methods for contact resistance reduction

Abstract

The development of advanced electronic devices is contingent upon sustainable material development and pioneering research breakthroughs. Traditional semiconductor-based electronic technology faces constraints in material thickness scaling and energy efficiency. Atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDs) have emerged as promising candidates for next-generation nanoelectronics and optoelectronic applications, boasting high electron mobility, mechanical strength, and a customizable band gap. Despite these merits, the Fermi level pinning effect introduces uncontrollable Schottky barriers at metal-2D-TMD contacts, challenging prediction through the Schottky-Mott rule. These barriers fundamentally lead to elevated contact resistance and limited current-delivery capability, impeding the enhancement of 2D-TMD transistor and integrated circuit properties. In this review, we succinctly outline the Fermi pinning effect mechanism and peculiar contact resistance behavior at metal/2D-TMD interfaces. Subsequently, highlights on the recent advances in overcoming contact resistance in 2D-TMDs devices, encompassing interface interaction and hybridization, van der Waals (vdW) contacts, prefabricated metal transfer and charge-transfer doping will be addressed. Finally, the discussion extends to challenges and offers insights into future developmental prospects.