A new metalorganic chemical vapor deposition process for MoS2 with a 1, 4-diazabutadienyl stabilized molybdenum precursor and elemental sulfur. Issue 38 (23rd September 2020)

• Record Type: Journal Article
• Authors: Wree, Jan-Lucas; Ciftyurek, Engin; Zanders, David; Boysen, Nils; Kostka, Aleksander; Rogalla, Detlef; Kasischke, Maren; Ostendorf, Andreas; Schierbaum, Klaus; Devi, Anjana
• Is Part Of: Dalton transactions. Volume 49:Issue 38(2020)
• Page Start: 13462
• Page End: 13474
• Publication Date: 2020-09-23
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt02471f
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Crystalline MoS2 thin films are deposited via MOCVD using a new molybdenum precursor, 1, 4-di- tert -butyl-1, 4-diazabutadienyl-bis( tert -butylimido)molybdenum(vi ) [Mo(N t Bu)2 ( t Bu2 DAD)], and elemental sulfur. Abstract : Molybdenum disulfide (MoS2 ) is known for its versatile properties and hence is promising for a wide range of applications. The fabrication of high quality MoS2 either as homogeneous films or as two-dimensional layers on large areas is thus the objective of intense research. Since industry requirements on MoS2 thin films can hardly be matched by established exfoliation fabrication methods, there is an enhanced need for developing new chemical vapor deposition (CVD) and atomic layer deposition (ALD) processes where a rational precursor selection is a crucial step. In this study, a new molybdenum precursor, namely 1, 4-di- tert -butyl-1, 4-diazabutadienyl-bis( tert -butylimido)molybdenum(vi ) [Mo(N t Bu)2 ( t Bu2 DAD)], is identified as a potential candidate. The combination of imido and chelating 1, 4-diazadieneyl ligand moieties around the molybdenum metal center results in a monomeric compound possessing adequate thermal characteristics relevant for vapor phase deposition applications. Hexagonal MoS2 layers are fabricated in a metalorganic CVD (MOCVD) process with elemental sulfur as the co-reactant at temperatures between 600 °C and 800 °C. The structure and composition of the films are investigated by X-ray diffraction, high resolution transmission electron microscopy, synchrotron X-ray photoelectron spectroscopy and Raman spectroscopy revealing crystalline and stoichiometric MoS2 films. The new MOCVD process developed for MoS2 is highly promising due to its moderate process conditions, scalability and controlled targeted composition.