Deposition of molybdenum nitride thin films by rf reactive magnetron sputtering

Molybdenum nitride thin films were prepared by the reactive r.f. magnetron sputtering technique, on grounded substrates, using nitrogen as reactive gas. The effect of the variation of nitrogen partial pressure and the substrate temperature on the microstructure of these films has been investigated. X-ray and electron diffraction studies were used to optimize the growth conditions leading to single-phase gamma-Mo2N thin films. The composition of the films was estimated using Auger electron spectroscopy studies. Single-phase f.c.c. gamma-Mo2N films exhibiting metallic conductivity have been obtained over a wide range of nitrogen partial pressure. The films were polycrystalline in nature having grain size in the range 10-25 nm. The preferred orientation of the crystallites and the lattice parameter are found to depend on the nitrogen incorporation in the film. The morphology of all the films lies in the zone T regime of Thornton's structure zone model. The resistivity of these films exhibits a dependence on the size and orientation of the grains and appears to be determined by grain-boundary-related effects. The microstructure of the films is not significantly influenced by a variation of the substrate temperature in the range 300-575 K.