Manufactureand Properties Analysis Of SrTiO₃ Ferroelectric Thin Films By Pulsed Laser Deposition

With the rapid development of microelectronics integration technology and the expanding of the miniaturization applications of related technologies such as optoelectronic and sensor applications, the development of ferroelectric materials show a very attractive prospect. The excellent performance of perovskite ferroelectric oxides makes itself long-standing research focus, especially in the thin film materials. Because thin films have a direct impact to devices'performance, and along with the development of the technology, various demands are put forward for the tech and quality of the thin film. They demand the size, the structure. There are also strict demands on morphology. In order to satisfy the desire we should do more research and get the achievement on research and examine accordingly.For this reasons, we outlines the history of the development of ferroelectric thin films and its research status in this article. In the experiment, we successfully prepared strontium titanate and barium titanate thin films as typical perovskite-type oxide by using pulsed laser deposition method. Through the testing about the material structure, surface morphology and optical properties, we research the relationship between the film properties and the preparation method.The main research contents are as follows:1. SrTiO₃ thin films were deposited on LaAlO₃(100) substrates by a pulsed Nd:YAG laser with a wavelength of 355nm. The SrTiO₃ thin films were grown in various substrate temperatures, partial pressure of oxygen, laser power and substrate. The thickness of the SrTiO₃ thin films was measured using a stylus profiler. Their microstructure and surface morphology were analyzed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Their optical character was characterized using optical transmission spectrum. In accordance with the above text result, the relation between the process parameter and the SrTiO₃ thin films'the structure and character was analyzed and discussed. The substrate temperatures, partial pressure of oxygen, laser power and substrate are all important process parameters. This can provide a good experimental data to the further analysis of SrTiO₃ thin films.2. BaTiO₃ thin films on MgO(100) substrates were manufactured by PLD using the triple-frequency harmonics of pulsed Nd: YAG laser with different partial pressure of oxygen. The thickness of the BaTiO₃ thin films was measured using a stylus profiler. Their microstructure and surface morphology were analyzed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Their optical character was characterized using optical transmission spectrum. The results show that: BaTiO₃ films exhibit amorphous structure. With the increasing of oxygen partial pressure, BaTiO₃ films'surface roughness gradually increased. BaTiO₃ films have strong absorption in the ultraviolet, visible band.