WS2 Transistors with Sulfur Atoms Being Replaced at the Interface: First-Principles Quantum-Transport Study

Chih-Hung Chung; Hong-Ren Chen; Meng-Ju Ho; Chiung-Yuan Lin

doi:10.1021/acsomega.2c08275

WS₂ Transistors with Sulfur Atoms Being Replaced at the Interface: First-Principles Quantum-Transport Study

ACS Omega. 2023 Mar 8;8(11):10419-10425. doi: 10.1021/acsomega.2c08275. eCollection 2023 Mar 21.

Authors

Chih-Hung Chung¹, Hong-Ren Chen¹, Meng-Ju Ho¹, Chiung-Yuan Lin¹

Affiliation

¹ Department of Electronics and Electrical Engineering and Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan.

Abstract

Reducing the contact resistance is one of the major challenges in developing transistors based on two-dimensional materials. In this study, we perform first-principles quantum-transport calculations by adopting a novel type of partially sulfur-replaced edge contact metal/WSX/WS₂ in order to lower the Schottky barrier height and in turn reduce the contact resistance. Here, the sulfur replacements produce a segment of the metamaterial WSX (X = P, As, F, and Cl), using group V or halogen atoms to substitute sulfur atoms on one side of a WS₂ monolayer. We further compare the effects of such sulfur replacements on the interface metallization and bonding. Such WSX-buffered contacts exhibit contact resistances as low as 142 and 173 Ω·μm for the p-type Pt/WSP/WS₂ and n-type Ti/WSCl/WS₂ edge contacts, respectively. Moreover, ab initio molecular dynamics is employed to observe a stable standalone WSX monolayer at room temperature.