Preparation of TiN Films by Ion Mixing and Vapor Deposition Technique and Their Pinhole Defect Evaluation
Hitoshi UCHIDA, Masato YAMASHITA and Kazumasa TOKUDA
Abstract:Titanium nitride (TiN) films for a wide range of applications were prepared by nitrogen ion irradiation with 2keV during titanium vapor deposition, I.e., ion mixing and vapor deposition technique. The TiN films deposited onto stainless steels exhibited the columnar structure with the preferential crystal growth of (111) or (200) plane, and they contained more or less pinhole defects. Pinhole defects of TiN films were evaluated potentiodynamically in a deaerated 0.5kmol/m3H2SO4+0.05Kmol/m3KSCN solution at 298K. The critical passivation current density icrit of TiN film decreased successfully with increasing film thickness and substrate temperature. Here, the area ratio of pinhole defects was evaluated by the ratio of icrit of coated and non-coated specimens. Based on such electrochemical evaluation, the optimum preparation conditions for the corrosion-resistive dry coating films were discussed. Key Words:Thin film, Titanium nitride (TiN), Ion mixing and vapor deposition, Pinhole defect, Anodic polarization, Critical passivation current density (CPCD) technique