Positron beam spectroscopy for the assessment of the structure and defect density of titanium nitride

The performance of thin films is generally determined by their microstructure. By controlling the microstructure using the process parameters available in most deposition technologies (substrate temperature, energy and intensity of ion bombardment, etc.) it is possible to optimize the properties of the coating for a given application. However, to achieve the best results it is necessary to have an appropriate non-destructive structure probe with which to assess the microstructure. Slow positron spectroscopy is an attractive technique to achieve this where the films contain small open volume defects such as intercolumnar voids or vacancies. Here we present recent results in the use of the technique to characterize titanium nitride films deposited by several different deposition technologies and will highlight the effects of defect density and columnar packing density on the results generated.