Synthesis and Characterization of Small Grain Sized Molybdenum Nitride Films

Abstract

ABSTRACTPolycrystalline, small grain sized, 15 μm thick MoxN (x=1 or 2) films, void of detectable concentrations of molybdenum oxides, have been prepared on 50 μm thick nitrided Ti substrates via conversion of precursor MoO3 films in a programmed reaction with NH3. The latter films were produced via liquid spray pyrolysis of an MoCl5/methanol mixture in air at 500° C. The reaction of MoO3 films with NH3 resulted in a two-phase MoxN mixture consisting of γ-Mo2N and δ-MoN. The change in density of MoO3(ρ=4.69 g/cm3) to γ-MoN (ρ=9.50 g/cm3) and δ-MoN (ρ=9.05 g/cm3) produced grains with a calculated average size of 10 nm without losing adherence to the substrate. The composition of the MoxN films was determined by X-ray diffraction (XRD) and Auger electron spectroscopy (AES) to be ∼ 60% γ-Mo2N and 40% δ-MoN. The results of scanning electron microscopy (SEM) showed the surface morphology of the MoxN films to be highly porous.