FILM THICKNESS DEPENDENCE OF DIELECTRIC PROPERTY AND CRYSTAL-STRUCTURE OF PBTIO3 FILM PREPARED ON PT SIO2 SI SUBSTRATE BY METAL-ORGANIC CHEMICAL-VAPOR-DEPOSITION

The crystal structure of PbTiO3 film, which was prepared on a Pt/SiO2/Si substrate by metal organic chemical vapor deposition, was investigated along with its dielectric properties. The relative dielectric constant increased with increasing film thickness. Crystal structure difference was observed below 0.3 mum of film thickness, as compared to that above 0.3 mum of thickness; i.e., the lattice constant ratio of the c-axis to a-axis, the intensity ratio of (00l) to (h00) reflections and the average crystallite size decreased, and the nonuniform stress increased with decrease in the film thickness. These crystal imperfections for below 0.3 mum thickness might be related to the existence of a low relative dielectric constant layer near the substrate.