Film Thickness Dependence of Dielectric Property and Crystal Structure of PbTiO3 Film Prepared on Pt/SiO2/Si Substrate by Metal Organic Chemical Vapor Deposition

Abstract

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 µm of film thickness, as compared to that above 0.3 µm 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 µm thickness might be related to the existence of a low relative dielectric constant layer near the substrate.