Abstract
This thesis studies the effect of structure and properties of TiN thin film by controlling thickness. The thin films were grown using hollow cathode discharge ion-plating (HCD-IP) on Si wafer and 304 stainless steel. Field Emission scanning electron microscope (FEG-SEM) and cross-sectional transmission electron microscope (XTEM) were used to characterize the thickness and structure of deposited TiN film. X-ray diffraction (XRD) was used to determine the preferred orientation. In the aspect of mechanical properties, hardness was measured by a ultra-microhardness tester and the ultimate interfacial shear stress was determined by in-situ substrate straining in an SEM. The composition depth profiles of TiN films were obtained using a secondary ion mass spectrometer (SIMS). The N/Ti ratios were measured by both X-ray photoelectron spectrometer (XPS) and Rutherford backscattering spectrometer (RBS). From the results of RBS, the packing factors of TiN films can also be obtained. The resistivity of TiN film was measured by four-point probe. The corrosion resistance were evaluated by standard salt spray test, and by potentiodynamic scanning in two kinds of solutions: 5% NaCl and 1N H2SO4 + 0.05M KSCN, respectively. The results show that (111) is found to be the dominant preferred orientation in most of the deposition conditions for both of Si and 304 stainless steel substrates, especially as film thickness greater than 1 mm. Comparing the N/Ti ratios measured by RBS with those by XPS, the results were slightly lower for XPS, which may be due to the preferential sputtering of N before XPS measurement. The hardness values of TiN film were 23 ~ 24 GPa, and were not changed with different substrate materials. The packing factor has a linear relationship with thickness and levels off when thickness larger than 1.2 mm. The resistivity decreases with increasing thickness for all coating angles. At a similar packing factor, specimens coated at angles different from 0。 have a much higher. From the results of potentiodynamic polarization, the influence of thickness and packing factor on the corrosion resistance is within different range. As the film thickness lower than 0.7 mm, the thickness is the dominant factor.