Ferroelectric Properties of (PbxLa1-x)(ZryTi1-y)O3 Thin Films Prepared by Modified Pulsed Laser Deposition Process

Abstract

A two-step pulsed laser deposition (PLD) process, including PLD at a substrate temperature lower than 150°C and rapid thermal annealing (RTA) at around 550°C (30 s), has been successfully applied for growing (PbxLa1-x)(ZryTi1-y)O3, (PLZT, x=0.97, y=0.664) thin films. Fatigue-free, large remanent polarization, Pr=19 µC/cm2, (with coercive field Ec=78 kV/cm and low leakage current density Jl ≤1 ×10-5 A/cm2 at 400 kV/cm) characteristics can be achieved when a SrRuO3 layer is used as a buffer layer. Interdiffusion between layers remains pronounced when an amorphous SrRuO3 layer is used as a buffer layer, which markedly degrades the electrical properties of PLZT films. Only the crystalline SrRuO3 layer can effectively suppress the interdiffusion of species and improve the ferroelectric behavior of the PLZT films. Such a modified PLD process possesses an overwhelming advantage over the in situ PLD process in terms of its simplicity and compatibility with device fabrication processes.