Control of Microstructure and Orientation in Solution-deposited BaTiO₃ and SrTiO₃ Thin Films
Columnar and highly oriented (100) BaTiO3 and SrTiO3 thin films were prepared by a chelate-type chemical solution deposition (CSD) process by manipulation of film deposition conditions and seeded growth techniques. Randomly oriented columnar films were prepared on platinumcoated Si substrates by a multilayering process in which nucleation of the perovskite phase was restricted to the substrate or underlying layers by control of layer thickness. The columnar films displayed improvements in dielectric constant and dielectric loss compared to the fine-grain equiaxed films that typically result from CSD methods. Highly oriented BaTiO3 and SrTiO3 thin films were fabricated on LaAlO3 by a seeded growth process that appeared to follow a standard “two-step” growth mechanism that has been previously reported. The film transformation process involved the bulk nucleation of BaTiO3 throughout the film, followed by the consumption of this matrix by an epitaxial overgrowth process originating at the seed layer. Both BaTiO3 and PbTiO3 seed layers were effective in promoting the growth of highly oriented (100) BaTiO3 films. Based on the various processing factors that can influence thin film microstructure, the decomposition pathway involving the formation of BaCO3 and TiO2 appeared to dictate thin film microstructural evolution.
R. W. Schwartz et al., "Control of Microstructure and Orientation in Solution-deposited BaTiO₃ and SrTiO₃ Thin Films," Journal of the American Ceramic Society, American Ceramic Society, Feb 1999.
Materials Science and Engineering
United States. Department of Energy
Keywords and Phrases
Chemical Solution Deposition; Crystal Microstructure; Crystal Orientation
Article - Journal
© 1999 American Ceramic Society, All rights reserved.