Evaluation of defect ratio in TiN film made by plasma CVD by CPCD method

摘要

Corrosion resistance of coated TiN film is governed by pinhole defect. Therefore, it is necessary to evaluate the existing state of defects. The Critical Passivation Current Density (CPCD) method had some problems though this method could quantitatively estimate defects as a pinhole defect ratio (%). The most important problem is the overestimation in defect ratio evaluation in the cases when large corrosion pits were generated and some parts of TiN films were exfoliated due to its low adhesion strength and high residual stress. Therefore in this study, the adhesion characteristics of TiN films which was coated by plasma CVD was investigated by the scratch test. The applicable range of the CPCD test was made clear for the defect ratio evaluation of TiN films with various film thickness and adhesion strength. And then, some improvements of CPCD test for avoiding the overestimation of defect in film are discussed.