Low Temperature Growth of Wafer-Scale 2D MoS₂ Thin Films By Pulsed Plasma-Enhanced Chemical Vapor Deposition

Abstract

Layered two-dimensional molybdenum sulfide (MoS 2 ) has attracted great interest for a promising candidate material for opto-electronic, sensing and catalysis applications due to its outstanding mechanical, electrical and optical properties. In order to apply MoS 2 to the industrial field, significant efforts have been placed in obtaining a wafer-scale uniform MoS 2 . There have been many progressions in various methods such as thermal-CVD [1] and ALD [2], but these methods have crucial limitation that they demand either high growth temperature or post-thermal treatment. In the present study, to overcome the limitation of traditional method, pulsed plasma-enhanced chemical vapor deposition was adopted for the growth of MoS 2 thin films. By using H 2 S plasma reactant, the growth temperature could be significantly lower than in the previous way. The pulsing of Mo precursor injection properly regulates the Mo precursor partial-pressure ratio that is crucial for the synthesis of MoS 2 . Through these strategies, mono to few layers of MoS 2 thin films was deposited uniformly on SiO 2 /Si substrates. X-ray photoelectron spectroscopy and transmission electron microscopy demonstrated the composition and crystallinity of MoS 2 thin films depends on the plasma conditions. Furthermore, through optimizing the plasma conditions, the potential of MoS 2 for electric device component was investigated. Fig1. (a) Raman spectra of MoS 2 thin films (b) XPS spectra of Mo 3d(left), S 2p(right) obtained from MoS 2 thin films deposited by pulsed PECVD. References [1] Hyun Cheol-Min, et al. Journal of Alloys and Compounds , 2018, 765: 380-384. [2] TAN, Lee Kheng, et al. Nanoscale , 2014, 6.18: 10584-10588. Figure 1