Preparation and electrical properties of Zr-rich PZT thin films by rf magnetron sputtering method using multitarget

Abstract

Zr-rich lead zirconate titanate (PZT) thin films with a thickness of 1 micrometer were successfully grown on (111)PLT/Pt(111)/Ti(101)/SiO2/Si(100) substrates by an rf planar magnetron sputtering equipment using a multi-target which consisted of PbO and metal titanium pellets on a zirconium metal plate. The optimum sputtering conditions were a gas content of Ar:O2 equals 8:2 Sccm, gas pressure of 6 X 10-3 Torr, rf power of 100 W and substrate temperatures of 630 - 650 degrees Celsius. The composition of the films could be controlled by adjusting the area ratio of PbO/Zr/Ti. The crystal structures of films were sensitive to the substrate temperature. The pyroelectric current, relative dielectric constant, remanent polarization and coercive field of the PZT films were measured. These electrical properties depending on the ratio of Zr/Ti in the films are described. The phase transition of low temperature to high temperature rhombohedral ferroelectric phases in as-grown PZT films is also reported. Zr-rich PZT films sputtered on (111)PLT/Pt/Ti/SiO2/Si substrate possess desirable properties for potential applications to pyroelectric devices.