Preparation of Ba_1−xSr_xTiO₃ Dielectric Film by Electrophoretic Deposition Method with Slurry

Abstract

In recent decades, a Ba_1−xSr_xTiO₃ film has been developed as a dielectric film for many electronic devices. In this work, we focused on an electrophoretic deposition method as a film-forming process, and prepared Ba_1−xSr_xTiO₃ (x=0∼0.3) films by the method using dispersed Ba_1−xSr_xTiO₃ slurries as the bath. As a result, it was found that the film thickness depended on the deposition voltage and time, and homogeneous film with a few µm of thickness could be obtained even with an electrophoretic deposition method by using the slurries. We also studied dielectric properties of the films after sintering. From the results, it was demonstrated that Ba_0.9Sr_0.1TiO₃ film, which was deposited for 4 sec at 80 V and then heat-treated at 1000°C for 15 min under N₂ flow, had 2.6 µm of a thickness, and exhibited 162 nF·cm⁻² of a capacitance density, 476 of a dielectric constant, 3.4% of a dielectric loss and 3.96×10⁻⁸ A·cm⁻² of a leak current.