Improvements of the properties of chemical-vapor-deposited (Ba,Sr)TiO3 films through use of a seed layer

(Ba,Sr)TiO3 (BST) thin films were deposited on seed-layer /Pt/SiO2/Si substrates by chemical vapor deposition and the properties of the films were investigated. The effect of rapid thermal annealing (RTA) was also examined. The seed layer used in this experiment was the 10-nm-thick BST him fabricated by RF magnetron sputtering. Both the application of the seed layer and RTA increased the crystallinity of the BST films, which resulted in improved dielectric properties of the films. The seed layer suppressed the formation of an oxygen-deficient layer at the interface between BST and the bottom electrode, which resulted in a decrease of the current density of the Pt/BST/Pt capacitor. Furthermore, the current density was further decreased by RTA. With increasing deposition temperature, both the dielectric constant and the current density of the BST films deposited on the seed layers increased.