Leakage Current Property of Pb(Zr0.4, Ti0.6)O3 Thin-film Capacitors with Highly Rectangular Hysteresis Property

The Pb(Zr0.4,Ti0.6)O3 thin-film capacitors with top and bottom Pt electrodes were prepared by chemical solution deposition using the precursor solutions with Pb contents ranging from 104 to 119%. Leakage current densities of the PZT capacitors monotonically decreased with increasing Pb contents. In the Pb110%-PZT capacitor, a conduction mechanism changed from the Schottky emission to the Poole-Frenkel at an electric field of approximately 80 kV/cm at RT while the leakage current was limited only by the Poole-Frenkel in case of less Pb contents. In the Pb110%-PZT capacitor, the Schottky barrier height and a relative permittivity were estimated to be 1.1 eV and 4.8, respectively, and the activation energy of trap sites in the Poole-Frenkel conduction was estimated to be 0.5 eV.