The Influence of N<sub>2</sub> Partial Pressure on Color, Mechanical, and Corrosion Properties of TiN Thin Films Deposited by DC Reactive Magnetron Sputtering

Abstract

Multi-functional thin films have gained increasing importance in a decorative application. Among the available material, titanium nitride (TiN) thin film is interesting due to its golden color and mechanical resistance. Beside their properties, the corrosion property of TiN films is mainly considered in order to extend the life time. In this work, the TiN thin films were deposited on 3x3 cm2 Si(100) substrates by dc reactive magnetron sputtering technique. The effects of N2 partial pressure (PN2) on deposited film properties such as microstructure, surface morphology, color, mechanical and corrosion properties were investigated. We found that the crystal structure of the TiN films exhibit the (200) preferred orientation. The color of TiN films change from gold-yellow to gold-red colors by increasing of N2 partial pressure that could be explained by Drude model. The TiN films have smoother surface when the N2 partial pressure increases. Standard corrosion tests in artificial sweat solution show the corrosion current density (icorr) in the range between 0.25 to 4.25 mA/cm2 and the polarization resistance increases with increasing of N2 partial pressure. The highest hardness of the film is approximately 40 GPa with elastic modulus of 340 GPa. We conclude that N2 partial pressure corelates with color, mechanical property and corrosion resistance of TiN films, which were optimized to use in decorative application.