Low Temperature Deposition of (Ba, Sr)TiO3 Films by Electron Cyclotron Resonance Plasma Chemical Vapor Deposition

(Ba, Sr)TiO3 films deposited by electron cyclotron resonance plasma chemical vapor deposition at 450° C and 500° C are investigated. The crystallinity, evaluated by X-ray diffraction and by measuring grain size, and electrical properties of films were evaluated for changes in deposition temperature, deposition rate, and Ba content, without a post-deposition annealing. Slower deposition rates as well as higher deposition temperatures were found to improve film crystallinity. Evaluation of electrical properties and film crystallinity revealed that the optimum Ba content of a film deposited at 500° C was 0.4. A 27 nm thick film deposited on a Pt substrate at 500° C and at 1.1 nm/min with a Ba content of 0.4 exhibited a SiO2 equivalent thickness of 0.65 nm and a leakage current density of 4.6×10-7 A/cm2 at 1 V. The film composition was found to be sufficiently uniform throughout, i.e., from the top to the side of the films on a stacked bottom electrode.