Preparation and Characterization of Barium Strontium Titanate Thin Films by Chemical Solution Deposition

Abstract

In the present study, Ba 0.70 Sr 0.30 TiO 3 thin films were realized by chemical solution deposition based on the use of an alkoxide precursor. The solution is spin-coated onto stainless steel substrates and a classical multi-layer technique was used in order to obtain thicker films. The elaboration route is described and a study of the temperature dependence of the crystallization process is presented. The ferroelectric and the dielectric (permittivity and tanδ) properties were determined at different temperatures in order to determine the evolution of the tunability and the figure of merit of the films.

Influence of the Morphology of Barium Strontium Titanate Thin Films on the Ferroelectric and Dielectric Properties

“…In the case of our study, the average thickness of one single layer, measured from SEM cross-section micro-graphs, is found to be about 400 nm, 180 nm, and 45 nm for the 0.6 M, 0.3 M, and 0.1 M solutions, respectively. For BST0.1M, some larger grains appear as the thickness of a single layer is close to the average grain size found in the BST film [8] thus favouring layer by layer grain growth in the case of multi-layer deposition. When using the sol-gel method for the elaboration of BST, crystallization into rather small grains is observed with an average grain size close to 50 nm.…”

“…Reducing the boundaries by increasing the average grain size thus seems to be an interesting approach which can be achieved by an enhanced annealing temperature [4]. The use of stainless steel substrates, however, does not allow too high annealing temperatures because of the substrate oxidation, and small grains and a high loss tangent were observed previously [8].…”

Temperature stable BaSrTiO3 thin films suitable for microwave applications

“…The manganese-doped Ba 0.80 Sr 0.20 TiO 3 thin films were realized by a modified sol-gel process based on the use of an alkoxide precursor [17]. The dilution was optimized in order to obtain a large grain size and to reduce the strain in the film [18].…”

Miniaturized and reconfigurable notch antenna based on a BST ferroelectric thin film

“…The Manganese induces the decrease of the oxygen vacancies in the ferroelectric thin film, which allows the reduction of the dielectric losses [10]. Mn 2+ doped Ba 0,80 Sr 0,20 TiO 3 films (hereafter noted BST) are produced by chemical solution route and spin-coating deposition [10,11]. Their growth is polycrystalline on stainless steel or alumina substrate [10,12] and their permittivities () are in the range [200 -500] depending on the Mn 2+ doping level, with dielectric losses less than 0.02 at 1 MHz [10].…”