Synergetic effect for improved deposition of titanium nitride films

It is known that cathodic arc deposition (CAD) has been widely used in industry for high quality thin film coatings. An extremely high current density (~1012 A/m2) was created to evaporate and ionize the target material rapidly. However, the CAD also produces macroparticles or droplets along with the deposition process leading to the degradation of the film properties. Magnetic filters with different designs were therefore adopted to reduce the macro particles or droplets. However, the macroparticles still cannot be fully eliminated. Lately, a newly developed PVD process known as high power impulse magnetron sputtering (HiPIMS) was found to have the capability of yielding highly ionized flux of both gas and sputtered materials by applying a high power in short pulses to the target. High plasma density in the order of 1017 to 1019 m−3, which is three orders of magnitude higher than that of the conventional dc magnetron sputter (dcMS), can therefore be achieved from the large fluxes of energetic ions in a HiPIMS process. As a result, a smoother and denser thin film with better adhesion to the substrate can be obtained, leading to enhanced mechanical, electrical, and optical properties. However, it was also found the deposition rate of the HiPIMS process was much slower than that of the conventional dcMS and CAD process. Therefore, a hybridized deposition system combining CAD and HiPIMS was studied in this paper. Titanium nitride (TiN) films were deposited to investigate their microstructures, physical, chemical, and mechanical properties. The macroparticles were reduced in the HiPIMS system while thin films with enhanced hardness was obtained in the CAD system.