TiN synthesized by filtered arc deposition combined with electron cyclotron resonance

Titanium nitride thin films possess many good properties including blood compatibility but the properties are strongly dependent on the fabricating process. In this work, TiN films were deposited on 316L substrate using filter arc deposition (FAD) combined with and without electron cyclotron resonance (ECR), and the properties of the two types of films were evaluated. The first group TiN films were deposited using the Ti ion beam produced by a filtered arc source in a nitrogen ambient, whereas the second set of samples were deposited using FAD with an ECR-sustained nitrogen plasma. X-ray diffraction (XRD) was employed to determine the structure, nano-indentation measurements were used to evaluate the hardness, atomic force microscopy (AFM) was utilized to evaluate the surface morphology, and pin-on-disk tribology tests were employed to assess the wear resistance. XRD results show that the films deposited by FAD with or without ECR process possess a single TiN phase, but the crystallographic orientation of the film changes from (111) to both (111) and (200) with the introduction of ECR excitation. This indicates that stress relief occurs during high energy bombardment or implantation and the thermal spike annealing effect is brought about by the ECR process. Nano-indentation results reveal that the nano-hardness of the samples synthesized by FAD with ECR can attain a value of about 15GPa, compared to 7.9GPa for the sample prepared by FAD alone. The film is densified with the stress changing from tensile or compressive due to the higher degree of ion bombardment from the ECR ignited plasma. AFM results disclose that both types of films are nano-sized crystalline and crack-free, but the surface of the FAD/ECR films tends to be rougher possibly due to more substantial sputtering effects. The friction coefficients and residual tracks revealed by pin-on-disk tests shows that the FAD/ECR film exhibits obviously higher wear resistance than that prepared by FAD alone and the enhancement can be explained by stress relief as well.