Crystallographic structure and composition of vanadium nitride films deposited by direct sputtering of a compound target

Abstract

Vanadium nitride thin films (VN) were sputter-deposited on silicon substrates in an argon gas atmosphere with a VN compound target. Nearly stiochiometric cubic VN films with different crystallographic orientations were achieved at ambient substrate temperature. The crystallographic structure of the film could be controlled through adjusting working argon pressure. Films with preferred (100) and (111) orientations were obtained at pressures of 0.5 and 2.0 Pa, respectively, regardless of the sputtering power; while amorphous film may form at a middle pressure of 1.0 Pa. Composition of the resultant films was analyzed by Rutherford backscattering spectroscopy. It was revealed that nitrogen deficiency was responsible for the amorphous state. The electronic states related to nitrogen vacancy were disclosed by valence band spectrum. The film compositional variation was discussed in the text.