Dielectric properties of (Ba,Sr)TiO sub(3) thin films with varied microstructures prepared by the chemical solution deposition method for thin-film capacitors and ferroelectric varactors

We prepared epitaxially grown three-axis-oriented (Ba sub(0.7)S sub(0.3))TiO sub(3) thin films on (100) platinum-coated (100) MgO single-crystal substrates by the chemical solution deposition method, using a solution derived from Ba(CH sub(3)COO) sub(2), Sr(CH sub(3)COO) sub(2), and Ti(O-i-C sub(3)H sub(7)) sub(4). Microstructures of fabricated thin films depend strongly on the fabrication process, especially on the annealing condition. A (Ba,Sr)TiO sub(3) thin film fabricated with an annealing temperature of 1073K was found to be a single crystal by transmission electron microscopy. The single-crystal (Ba,Sr)TiO sub(3) thin film exhibited a (100) threea-xis-orientation, which followed the (100) orientation of the platinum electrode on the MgO single-crystal substrate. A (100) three-axis-oriented (Ba,Sr)TiO sub(3) thin film may be useful for preparing a thin-film capacitor.