Chemical Vapor Deposition of MoS₂ and TiS₂ Films from the Metal-Organic Precursors Mo(S-t-Bu)₄ and Ti(S-t-Bu)₄

The deposition of MoS₂ and TiS₂ thin films from the metal-organic precursors Mo(S-t-Bu)₄ and Ti(S-t-Bu)₄ has been investigated. Stoichiometric films with low levels of oxygen and carbon contaminants can be grown at temperatures between 110 and 350°C and low pressure. The films are amorphous when grown at these low temperatures and have granular morphologies in which the grains are 30-90 nm in diameter, the larger grain sizes being observed at higher deposition temperatures. For the MoS₂ deposits, the electrical conductivity was ∼1 Ω^-1cm^-1. For both precursors, the organic byproducts generated during deposition consist principally of isobutylene and tert-butylthiol; smaller amounts of hydrogen sulfide, isobutane, di-tert-butyl sulfide, and di-tert-butyl disulfide are also generated. A β-hydrogen abstraction/proton-transfer mechanism accounts for the distributions of the organic byproducts seen during the deposition of MoS₂ and TiS₂ films. Our results differ in some respects from those of a previous study of the deposition of thin films from the titanium thiolate precursor.