Characterization of argon etched Ta${}_2$O${}_5$ thin films

Tantalum pentoxide finds use in many electronic and optical applications, and in the recent years has been highly important for use in optics. Its sought-after properties include dielectric insulation and optical reflectivity. Its full potential seems not yet fully tapped and further research into the material brings ever more possibilities of use. To further the development of Tantalum pentoxide-based technologies, this paper explores the properties of thin film coating created by electron beam evaporation with plasma ion assisted deposition on a silicon substrate. Ion etching is a highly popular and precise method of surface alteration, as it allows for alteration on nanoscale and better control over optical properties of the resulting sample. In our paper, etching was used to increase the topographical variability of the surface, while not breaching the tantalum pentoxide coating. The sample is subjected to several different measurement methods: X-ray diffraction and ellipsometry were used to establish the quality and integrity of the material, and optical reflectometry, X-ray photoelectron spectroscopy and atomic force microscopy were used for characterization of argon etching results. Optical and morphological properties and their relationship before and after etching are observed and documented to improve the knowledge about the material and set a baseline for future development.