Processing effects on the composition and dielectric properties of hydrothermally derived BaxSr(1-x)TiO3 thin films

Polycrystalline BaxSr(1-x)TiO3 (BST) thin films were processed on Pt-coated glass substrates at temperatures below 100 degreesC by reacting TiO2 films in alkaline solutions containing Ba2+ and/or Sr2+. The TiO2 was deposited by spin-casting a titanium metalorganic precursor onto Pt-coated glass subs trates, followed by pyrolysis in air at 400 degreesC. Film stoichiometry de viated from the initial solution composition, with a preferred incorporatio n of Sr2+ into the perovskite lattice. The BST thin films had dielectric co nstants ranging from 100 to 185 and dielectric loss values below 0.25. Capa citance-voltage and current-voltage relationships were examined to determin e the effect of phase stoichiometry and processing route on dielectric prop erties.