Investigation of BST thin films deposited by RF magnetron sputtering in pure Argon

Ba0.5Sr0.5TiO3 (BST) thin films were deposited by rf magnetron sputtering using a Ba0.5Sr0.5TiO3 target in pure Argon on two electrodes (Pt and RuO2) at room temperature. The interface formation between BST and bottom electrode (Pt or RuO2) was investigated by XPS for thicknesses in the 1 to 50 nm range. The chemical composition of the BST layers can be modified by the electrode nature over the first five nanometers. A 1 h ex-situ annealing, under flowing oxygen at 600 °C, was necessary to obtain crystallized 150 nm thick BST films, as evidenced by XRD and TEM analysis.