Systematic investigation of the ion beam sputter deposition process of TiO2

• Applicant: Dr. Carsten Bundesmann
• Subject Area: Glass, Ceramics and Derived Composites ; Synthesis and Properties of Functional Materials
• Term: from 2010 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 191257240

The overall goal of the proposed project is the generation of new knowledge concerning the understanding of the ion beam sputter deposition process, which shall allow the optimization of film properties of thin films for different applications. Thus, it is intended to contribute to the growing demand for thin films with tailored properties.The intended project shall considerably extend the fundamental and successfully performed investigations from befor project. The previous project addressed the comprehensive and systematic investigations of the ion beam sputter deposition process of monoatomic materials (namely Ag and Ge), i.e. the study of the systematic relations between the process parameters (primary ion energy, ion species, ion incidence angle, polar emission angle), the properties of the film-forming particles (angular and energy distributions of sputtered target particles and scattered primary particles), and the film properties.In the proposed project these systematic investigations shall be extended to the sputtering process of multiatomic systems, because systematic differences in respect to sputtering of a monoatomic target are expected, or instance, preferential sputtering of the target constituents and the generation of more than one sputtered species, namely, the generation of atoms, ions and molecules. The different particle species tentatively possess different angular and energy distributions, which have different dependencies on the process parameters. So far, there have been published no results which have addressed these questions. Exemplarily, TiO2 is chosen as the considered material. TiO2 is of technological interest because of certain material properties, i.e. its photo activity or its optical properties. Because of that, TiO2 is used as photo catalyst, in solar cells or in optical multilayer coatings.There are two technological approaches for the deposition of TiO2 by sputtering. The first approach is the reactive deposition from a metallic Ti target. Here the metallic component is sputtered whereas the oxygen is provided as a process gas. The second approach is the direct sputtering of ceramic TiO2 target. In this case all film constituents are sputtered from the target. Thus, the two approaches differ from the energy entry into the growing layer, which should result in different film properties. The following tasks shall be done within the proposed project: The experimental measurement of the properties of the film forming particles and of the films, and their relations under systematic variation of the process parameters. These experiments shall be performed for both the direct and the reactive deposition process. In addition, simulations of the sputter process will be performed, which shall help to validate the simulation code and, hence, its usability in the concrete case.

• DFG Programme: Research Grants