Effects of film thickness and grain size on the electrical properties of Pb(Zr,Ti)O3 thin films prepared by MOCVD

Abstract

In order to eliminate the grain size effects from the thickness dependence of the electrical properties, we measured the electrical properties of epitaxial and polycrystalline Pb(Zr, Ti)O3 (PZT) thin films. Epitaxial and polycrystalline PZT thin films were prepared by MOCVD on SrRuO3/SrTiO3 and SrRuO3/SiO2/Si, respectively. Thickness dependence of the I-V characteristics, relative dielectric constant, remanent polarization, and coercive field were investigated in a thickness range from 40 to 440nm. Thickness dependence of the electrical properties can generally be explained by the interfacial layer model. However, the behaviors of high leakage current density and strong thickness dependence for polycrystalline films are understood by the grain size effect and the presence of grain boundary. The 40nm-thick epitaxial and 50nm-thick polycrystalline PZT films showed good D-E hysteresis loops.