Systematic investigation of the ion beam sputter deposition process of TiO2

拟议项目的总体目标是产生关于理解离子束溅射沉积过程的新知识，这将使薄膜的性能能够针对不同的应用进行优化。因此，它旨在促进对具有定制特性的薄膜不断增长的需求。计划中的项目将极大地扩展之前项目的基础研究并成功地进行了研究。以前的项目是对单原子材料(即银和锗)的离子束溅射沉积过程进行全面和系统的研究，即研究过程参数(一次离子能量、离子种类、离子入射角、极发射角)、成膜粒子的性质(溅射靶粒子和散射一次粒子的角度和能量分布)和薄膜性质之间的系统关系。在拟议的项目中，这些系统的研究将扩展到多原子系统的溅射过程，因为关于单原子靶材的溅射可能存在系统差异，例如，优先溅射靶成分和产生一个以上的溅射物种，即原子、离子和分子的产生。不同的粒子物种暂时具有不同的角度和能量分布，这些分布对工艺参数有不同的依赖关系。到目前为止，还没有发表任何解决这些问题的结果。例如，选择二氧化钛作为考虑的材料。由于材料的某些性质，即它的光活性或光学性质，二氧化钛在技术上引起了人们的兴趣。正因为如此，二氧化钛被用作光催化剂，用于太阳能电池或光学多层膜。溅射沉积二氧化钛有两种技术途径。第一种方法是从金属钛靶上反应沉积。在这里，金属成分是溅射的，而氧气是作为工艺气体提供的。第二种方法是直接溅射陶瓷二氧化钛靶材。在这种情况下，所有的薄膜成分都从靶上溅射出来。因此，这两种方法不同于能量进入生长层，这应该导致不同的薄膜特性。在拟议的项目中，将完成以下工作：对成膜颗粒和薄膜的性质以及它们在工艺参数系统变化下的关系进行实验测量。对于直接沉积过程和反应沉积过程都应进行这些实验。此外，还将对溅射过程进行模拟，这将有助于验证模拟代码，从而验证其在具体情况下的可用性。

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.