Dielectric properties of (100) textured thick Pb(ZrxTi1−x)O3 films with different Zr/Ti atom ratios

Abstract

Near 4-μm-thick Pb(ZrxTi1−x)O3 (PZT) films with Zr/Ti ratios of 60/40, 52/48, and 45/55 were coated onto platinized silicon substrates by using 2-methoxyethanol based sol-gel spin-on techniques with a special thermal treatment process. The scanning electron microscopy observations show the columnar growth of grains. The analysis of x-ray diffraction data indicates that all PZT films exhibit (100) texture. The dielectric constants and dissipation factors of the films were measured at elevated temperatures and frequencies. It is found that Curie points of 60/40, 52/48, and 45/55 films are at 350, 375, and 422 °C, respectively. All these films exhibit high dielectric constants and remnant polarizations. A permittivity of 1658 and remnant polarization of 35 μC/cm2 had been achieved for the 60/40 films. No enhancement of the dielectric constant was observed in films with a Zr/Ti ratio close to morphotropic phase boundary. The high dielectric constant observed in films with the higher Zr content was explained by the concept of domain engineering.