Perovskite Oxide Film In The Stress Release Mechanism In The Study

With the rapid development of modern microelectronics and integrated circuits, electronic devices with higher reliability, smaller size, and greater functionality are more popular. This requires the development of electronic components towards integration, miniaturization and multi-functional. The development of thin film device will put forward higher requirements for materials in electronic components.Perovskite oxide thin films have been aroused a great deal of attention, due to its unique properties such as dielectric tunability, multiferroic, superconductivity and ferromagnetic coupling. However, with limitations of existing technologies, during the manufacturing process of perovskite oxide thin films, it is inevitable to produce defects and stress during the fabrication, which will affect the physical and chemical properties of the thin films. The study of stress and defects generation and stress-release mechanism is critical for the production of perovskite oxide thin films with higher performance.In this paper, X-ray diffraction method will be applied on testing the lattice constants and defect densities of several representative thin films in the perovskite system, with the purpose of investigating the strain relaxation mechanism in the perovskite system and providing some theoretical basis for further optimization of the performance of perovskite oxide thin films. This dissertation will include the following aspects:1. We will study the strain relaxation behavior of (Pb, Sr)TiO3thin films grown on NdGaO3substrate under different cooling rates, to explore the impact of the different cooling rates to the (Pb,Sr)TiO3thin film strain and possible strain relaxation mechanisms.2. We will study the strain relaxation behavior of SrRuO3thin films grown on LaAlO3substrate under different deposition temperature, to explore the impact of the different deposition temperature to the SrRuO3thin film strain and possible strain relaxation mechanism.3. We will study the strain relaxation behavior of BaTiO3/SrTiO3multilayer thin films grown on LaAlO3substrate with different starting layer, to explore the impact of the different starting layer to the BaTiO3/SrTiO3multilayer thin film strain and possible strain relaxation mechanism.4. We will study on the strain relaxation behavior of LaBaCoO3thin films grown on different substrates, such as STO, MgO and NGO, to explore the impact of the different substrates to the LaBaCoO3thin film strain and possible strain relaxation mechanism.