Polycrystalline (1 - x)Ta2O5 - xTiO(2) thin films were formed on Si by metalorganic decomposition (MOD) and annealed at various temperatures. As-deposited films were in the amorphous state and were completely transformed to crystalline after annealing above 600 degreesC. During crystallization, a thin interfacial SiO2 layer was formed at the (1 -x)Ta2O5 - xTiO(2)/Si interface. Thin films with 0.92Ta(2)O(5)-0.08TiO(2) composition exhibited superior insulating properties. The measured dielectric constant and dissipation factor at 1 MHz were 9 and 0.015, respectively, for films annealed at 900 degreesC. The interface trap density was 2.5 x 10(11) cm(-2) eV(-1), and flatband voltage was -0.38 V. A charge storage density of 22.8 fC/mum(2) was obtained at an applied electric field of 3 MV/cm. The leakage current density was lower than 4 x 10(-9) A/cm(2) Up to an applied electric field of 6 MV/cm. (C) 2002 Elsevier Science B.V. All rights reserved.