Special Issue Ceramics Integration. Change of Residual Stresses and Electrical Properties of Pb(Zr,Ti)O3 Thin Films Upon Introducing Various Bottom Electrodes.

Abstract

Effects of Pb(Zr0.5Ti0.5)O3 (PZT) thickness on the residual stresses and the electrical properties of a PZT thin-film layer were discussed for the PZT/Pt/SrTiO3 or PZT/(La0.5Sr0.5)CoO3/SrTiO3 system. Bottom electrodes, i.e., Pt and (La, Sr)CoO3 (LSCO) thin films, were deposited by DC magnetron sputtering and pulsed laser deposition (PLD), respectively. PZT thin films with thicknesses of 30nm and 60nm were fabricated using the pulsed metal-organic chemical vapor deposition (MOCVD) apparatus. PZT films deposited on the LSCO electrodes were all epitaxially grown. The residual stress measurements by XRD revealed that all PZT films received the in-plane tensile stress from the substrate or the electrode/substrate. When the Pt and LSCO electrodes were introduced between the PZT film and the STO substrate, in-plane tensile stress in PZT was enhanced. With decreasing the PZT film thickness, the in-plane tensile stress in PZT film was enhanced. Remanent polarization decreased with increasing residual tensile stress in PZT film in all cases. The change of residual stress in the PZT/LSCO/STO system was discussed on the basis of the thermal expansion coefficient of the constituent layers.