SOME ASPECTS ABOUT STRUCTURAL AND TRIBOLOGICAL CHARACTERIZATION OF REACTIVE MAGNETRON SPUTTERED TiN THIN FILMS

摘要

The paper presents the influence of preparation conditions, such as DC power applied at the Ti target and bias voltage, on some physical/structural and mechanical behavior of TiN thin films, deposited by DC magnetron sputtering in the low-pressure range. Regarding structural characterization, a preferred orientation with the fcc {111} planes parallel to surface was observed. By increasing the dc power on the Ti target or increasing the substrate bias, the texture effect in the films is favored. Tribological and mechanical properties such as static friction coefficient, wear, adhesion and residual stresses are characterized and discussed as a function of structural properties and the deposition parameters. A minimum value of static friction coefficient was obtained for the unbiased sample, which presented a very good tendency for sliding. A low level of compressive stresses was also obtained in this sample. With increasing ion bombardment the friction properties become worse. The wear test results seem to show a good correlation between the wear tests and the friction behavior. Thermal anneals in vacuum at 800℃ were performed on these samples, revealing that the coatings maintained their favored crystalline texture with an increase in both grain size and lattice parameter due to the relaxation of the high compressive stresses. A statistical analysis was performed on the surface defect density of the TiN thin films, which concluded that as the negative bias voltage increased the defect density and average defect area also increased.