Sulfidation characteristics of amorphous nonstoichiometric Mo-oxides for MoS2 synthesis

• Published in: Applied surface science 2021-01, Vol.535, p.147684, Article 147684
• Main Authors: Kim, Hoijoon, Park, Taejin, Leem, Mirine, Lee, Hyangsook, Ahn, Wonsik, Lee, Eunha, Kim, Hyoungsub
• Format: Article
• Language: English
• Subjects: Amorphous Mo-oxide; MoO2; MoO3; MoS2; Sulfidation
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2020.147684

[Display omitted] •Sulfidation characteristics of amorphous MoO3−x films evaporated from MoO3 and MoO2 are compared.•More largely-reduced MoO3−x is appropriate for formation of a continuous MoS2 film.•Thickness and sulfidation temperature are optimized to produce a MoS2 monolayer.•Operation of bottom-gated transistors with a synthesized MoS2 film is demonstrated. In this study, the thermal sulfidation characteristics of two amorphous nonstoichiometric Mo-oxide (MoO3−x) films were investigated that were deposited using e-beam evaporation of MoO3 and MoO2 powders. It was observed that evaporation of MoO2 produced an amorphous MoO3−x film that exhibited a greater number of low oxidation states than that obtained by MoO3 evaporation. Moreover, subsequent sulfidation allowed the formation of a continuous MoS2 film; meanwhile, the MoO3-evaporated sample transformed into a discontinuous MoS2 film. Both the initial thickness of the MoO2-evaporated film and the sulfidation temperature were varied to determine their effects on the final MoS2 film quality. The sulfidation of an approximately 1-nm-thick MoO2-evaporated film at 780 °C produced a predominantly monolayer MoS2 film. Further, an operation of the bottom-gated transistor arrays using the synthesized MoS2 film was demonstrated along with a preliminary experimental result for potential application in three-dimensional device integration.