The fabrication and characteristics of (Ba0.5Sr0.5)Ti-0.3 (BST) thin films prepared by sputtering (Ba0.5Sr0.5)TiO3 targets were investigated. The laser-deposited BST films were grown on Si (100) substrates at 700degreesC under an oxygen pressure of 0.1 Pa. The capacitance-voltage behavior of metal-insulator metal structures and their leakage current characteristics were studied. The results showed that the dielectric constant of 40 nm thick BST films was 150, and the dissipation factor was 0.035 at 1 MHz. The leakage current density was 2 x 10(-9) A/cm(2) at 2V. The high dielectric constant, low dielectric loss, and low leakage current show the potential of (Ba0.5Sr0.5)TiO3 thin films for integrated capacitors and high-density dynamic random access memories. (C) 2002 Elsevier Science B.V. All rights reserved.