A new metalorganic chemical vapor deposition process for MoS2with a 1,4-diazabutadienyl stabilized molybdenum precursor and elemental sulfur

Wree, J.-L. and Ciftyurek, E. and Zanders, D. and Boysen, N. and Kostka, A. and Rogalla, D. and Kasischke, M. and Ostendorf, A. and Schierbaum, K. and Devi, A.

Volume: 49 Pages: 13462-13474
DOI: 10.1039/d0dt02471f
Published: 2020

Molybdenum disulfide (MoS2) is known for its versatile properties and hence is promising for a wide range of applications. The fabrication of high quality MoS2either as homogeneous films or as two-dimensional layers on large areas is thus the objective of intense research. Since industry requirements on MoS2thin 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(NtBu)2(tBu2DAD)], 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 MoS2layers 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 MoS2films. The new MOCVD process developed for MoS2is highly promising due to its moderate process conditions, scalability and controlled targeted composition. © The Royal Society of Chemistry 2020.

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