Structural Evolution of Molybdenum Disulfide Prepared by Atomic Layer Deposition for Realization of Large Scale Films in Microelectronic Applications

Journal Article · Mon Jul 23 20:00:00 EDT 2018 · ACS Applied Nano Materials

DOI: https://doi.org/10.1021/acsanm.8b00798 · OSTI ID:1788155

Letourneau, Steven  ^[1]; Young, Matthias J. ^[2]; Bedford, Nicholas M. ^[3]; Ren, Yang ^[2]; Yanguas-Gil, Angel ^[2]; Mane, Anil U. ^[2]; Elam, Jeffrey W.  ^[2]; Graugnard, Elton  ^[4]

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1. Boise State Univ., ID (United States); Boise State University
2. Argonne National Lab. (ANL), Argonne, IL (United States)
3. Univ. of New South Wales, Sydney, NSW (Australia); Air Force Research Lab. (AFRL), Wright-Patterson AFB, OH (United States)
4. Boise State Univ., ID (United States)

Molybdenum disulfide (MoS₂) films are attractive materials for electronic and optoelectronic devices, but the temperatures used in the chemical vapor deposition (CVD) of these materials are too high for device integration. Recently, a low-temperature atomic layer deposition (ALD) process was demonstrated for growth of MoS₂ films at 200 °C using MoF₆ and H₂S. However, the as-deposited films were amorphous and required annealing to obtain the desired layered structure. The MoS₂ films were sulfur-deficient; however, after annealing the crystallinity improved. To study the structure of these films and the process by which they crystallize, we performed in this work X-ray absorption spectroscopy and high-energy X-ray scattering experiments on both as-deposited and annealed MoS₂ films. Analysis indicated that molybdenum atoms in the as-deposited films were well coordinated with sulfur but not well coordinated with other molybdenum atoms when compared to a crystalline reference. Further analysis revealed clusters of the sulfur-rich phase [Mo₃S(S₆)₂]^2–, which decomposed after annealing in H₂ and H₂S at 400 and 600 °C. When compared to the sulfur-deficient films reported previously for this ALD process, the sulfur-rich phase found here indicates that nucleation on the substrate plays an important role in the resulting film stoichiometry, which could be tuned to produce higher quality films for microelectronic applications.

• Research Organization: Boise State Univ., ID (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Workforce Development for Teachers and Scientists (WDTS)
• Grant/Contract Number: AC02-06CH11357; SC0014664
• OSTI ID: 1788155
• Journal Information: ACS Applied Nano Materials, Journal Name: ACS Applied Nano Materials Journal Issue: 8 Vol. 1; ISSN 2574-0970
• Publisher: American Chemical Society (ACS)Copyright Statement
• Country of Publication: United States
• Language: English