UV exposure of zirconium sol-gel layers on Si with 5, 15 25 at.% Zr at 400 degreesC in O-2 for 20 min has led to the formation of high quality Zr silicate layers exhibiting low-leakage current densities of 3 X 10(-5) A/cm(2) at 1 MV/cm(2) for the 5% Zr layers, and even lower values of 9 X 10(-7) and 2 X 10(-7) A/cm(2) for the 15 and 25% Zr silicate layers, respectively. Annealing of these UV irradiated samples for 30 s at 1050 degreesC in a N-2 gas flow did not cause significant changes in leakage current density at biases up to 0.7 MV/cm. The formation of Si-O-Zr bonds led to a shift of the Si-O stretching vibration towards lower wavenumbers from 1050 to 1016/cm. X-ray diffraction analyses showed that these Zr silicate layers assumed an amorphous structure after UV exposure at 400 degreesC, and remained amorphous and stable following the high-temperature annealing at 1050 degreesC without separating into phases of crystalline ZrO2 and SiO2. (C) 2003 Elsevier B.V All rights reserved.