Innovative RF-magnetron sputtering process creates homogenous BaTiO3 films for high-tech electronics

Microstructural characterization of BaTiO3 thin films prepared by RF-Magnetron sputtering using sintered targets from high energy ball milled powders

The electronic and optical characteristics of barium titanate (BT) ferroelectric ceramics are of great interest for industrial uses and when grown as thin films they can easily be integrated into modern circuitry. These thin films are commonly prepared by RF- magnetron sputtering using a commercially available BT target as the material source.

The problem with using commercial BT-targets is that they fracture during the cathodic erosion, causing heterogeneities in subsequent film deposition procedures.

In this study, published in AZojomo*, by V. Torres-Heredia, J. Muñoz-Saldaña, F. J. Espinoza Beltrán, A. Márquez Herrera and A. Zapata Navarro from Unidad Querétaro and Unidad Altamira, BaTiO3-thin films were prepared by RF-sputtering using low temperature sintered BT-targets from powders processed by high energy ball milling. The films were deposited onto silicon (Si(111)) substrates coated with indium tin oxide (ITO), where the ITO thin film acts as an electrode. Furthermore, structure and microstructural characterization of the nanocrystalline BT thin films was reported.

Results indicated that the low BT sintering temperatures (950°C) produced the best microstructural properties of the target such as submicrometric grain size (~260 nm). This in turn lead to a high degree of densification and homogeneity. The microstructure of the resultant film was found to be strongly dependent on the annealing temperature, which also influenced internal stresses and the crystalline structure of the film.