Mechanical and microstructural changes of magnetron sputtered TiN films with various magnetic field configurations

Abstract

TiN coatings were deposited in a single magnetron sputter ion plating system in “balanced” and unbalanced mode with a closed magnetic field configuration. The film microhardness, thickness, adhesion, microstructure, preferred orientation and topography were analyzed as a function of the substrate position inside the deposition volume. In the static deposition mode and under the limitations of the experimental set-up used, no real homogeneous deposition conditions were achieved, but a significant possibility of controlling the spatial distribution of deposition conditions was demonstrated. The variation of the coating microhardness over the target-to-substrate distance, d S–T, ranging from about 80 to 210 mm was acceptable for practical applications, while the critical load for adhesive failure was found to decrease significantly with increasing d S–T in a balanced magnetron configuration. The variation of magnetic field configuration provided a relatively homogeneous distribution of the bias current density over the deposition volume, but the preferred orientation of the coating was changed from (200) to (111) with increasing d S–T. The energy delivered per unit volume of growing film, S E, and bombarding ion to deposited metal atom flux ratio j i/ j m were considered. It was found that j i/ j m can be used to describe qualitatively the change of preferred crystalline orientation of coatings.