| Because the properties of polycrystalline thin films depend strongly on their microstructure, an important research field is concerned with the control of this microstructure, particularly the grain size and texture are important microstructural characteristics which influence the mechanical and electromigration properties of thin films. Therefore, it is very necessary to control grain size and texture of thin films for the reliability and functionality. Ag is a kind of potential film material in the high-tech realm such as magnetic storage media and microelectronic devices. In recent years, it was extensively applied to the large-scale integrated circuit due to lower electrical resistivity and higher resistance to electromigration than those of Al, which draws the interest of many researchers.In this paper, the Ag thin films were deposited on single-crystal (111) -Si wafer by magnetron sputtering. The thickness of Ag films was 2 urn. The Ag thin films were grouped into Ag attached films and Ag free-standing films, then they were annealed in the quartz vacuum carousel furnace at deferent temperatures for various periods of time. Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray diffractometer (XRD) were applied to analyze those Ag films. Our works and conclusions were organized as follows:(1) Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Selected area electronic diffraction (SAED) were applied to analyze these samples. We can see that these Ag films were polycrystalline and face-centered-cubic structure (FCC). For films annealed, the average size of Ag grains was from 100 to 200 nm. SAED patterns showed that there was an abnormal large grain with (111) plane parallel to the film planes in Ag free-standing film. However, there was an abnormal large grain with (112) plane parallel to the film planes in Ag attached film.(2) X-ray diffractometer (XRD) was applied to analyze the texture of those Ag films. For these attached films after annealing, the number of Ag grains with (100) planes parallel to the film surface increased. On the contrary, for these free-standing films after annealing, the number of Ag grains with (111) planes parallel to the filmsurface increased. In order to quantitatively determine the texture of the Ag as-deposited and attached films annealed at 300 C for 4h, their (111), (200), (220) and (113) pole figures were measured using the Schultz reflection pole figure device, from which orientation distribution functions (ODFs) and inverse pole figures (IPFs) were calculated by Bunge's series expansion method with a maximum degree of 22 in a series of spherical surface harmonics. The main orientation components in specimens were (111) and (100) plane parallel to the films plane. However, after annealing, the attached Ag film showed an increase of gains with (111) and (100) preferred orientations.(3) ODF was calculated by Roe's method with one dimension data of the Ag(111), (200) and (220) three pole figures. For fiber texture, Roe's method was better than that of Bunge in measurement and treatment of pole figures for fiber texture.(4) A simple theory analysis is presented for grain growth (normal grain growth and abnormal grain growth) and the texture change of thin films. In FCC thin films, surface energy minimization often promotes the growth of grains with (111) planes parallel to the film surface. In contrast, strain energy minimization can lead to the growth of grains with (100) planes parallel to the film surface. The final grain size and the texture depend on the relative magnitudes of the driving forces, which can also be influenced by the experimental parameters and post-deposition process such as annealing.
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