Structural and electrical investigation of laser annealed (Pb,Sr)TiO3 thin films

Abstract

Material and electrical characteristics of (Pb,Sr)TiO3 (PSrT) films irradiated by various laser pulses and laser fluences are investigated in this work. Enhanced crystallinity can be obtained after excimer laser annealing (ELA). However, grain growth induced by ELA is nonuniform, and the effect is limited to the upper region of the films. As the number of laser pulses increases to 120, the film shows stronger diffraction intensities and increased oxygen content, resulting in a distinct capacitance versus electric field hysteresis loop and a larger dielectric constant than the nonirradiated one. The leakage current is found to be associated with the interface quality. The conduction mechanism of nonirradiated and irradiated PSrT films is mainly governed by Schottky emission at low electric fields, whereas the Poole-Frenkel emission occurs for films irradiated with more than 120 laser pulses or laser fluences larger than 90.5 mJ/cm(2) at high electric fields. (C) 2008 American Vacuum Society.