Influence of Cation Stoichiometry of la1-xSrxCoO3 Bottom Electrodes on the Orientation and Ferroelectric Properties of Pb(Ta0.05ZrO0.48Ti0.47)O3 Films

Abstract

AbstractThe Ta-doped PZT films (PTZT) were deposited on Pt/TiO2/SiO2/Si(001) substrates by pulsed laser deposition using La1-xSrxCoO3 buffer layers. The grain orientation of PTZT films is strongly influenced by the cation ratio of La1-xSrxCoO3. The PTZT films deposited using La0.75Sr0.25CoO3 with rhombohedral structure prefer (110)-orientaion, and those deposited using La0.25Sr0.75CoO3 with psuedo-cubic structure prefer (001)-orientation. It is found that the fatigue property of the PTZT capacitors can be improved enormously by using (001)-oriented La0.25Sr0.75CoO3 bottom electrodes. SEM morphology pattern for the surface of PTZT films and for the cross-section show that no obvious interdiffusion occurs across the interfaces. The ferroelectric capacitor La0.25Sr0.75CoO3/PTZT/La0.25Sr0.75CoO3/Pt/TiO2/SiO2/Si(001) shows almost no degradation in its polarization after 1.5×1010 switching cycles at an applied voltage 5 V and a frequency 1MHz.