Enhanced ferroelectric properties of Pb(Ta0.05Zr0.48Ti0.47)O3 thin films on Pt/TiO2/SiO2/Si substrates using La0.67Sr0.33MnO3 buffer layers

Abstract

Highly 111 oriented Pb(Ta0.05Zr0.48Ti0.47)O3 (PTZT) ferroelectric thin films were deposited on Pt/TiO2/SiO2/Si substrates using a La0.67Sr0.33MnO3 (LSMO) buffer layer. It is found that the LSMO buffer layers induced highly (111) textured growth of PTZT films. Ferroelectric hysteresis measurements showed that the remnant polarization and coercive field of these films are about 20 µC cm-2 and 20 kV cm-1, respectively. After 1 × 1011 switching cycles at 5 V (about 100 kV cm-1 applied field) in fatigue tests, the decay of non-volatile polarization of these films was only about 6% of the initial value. No significant degradation of the polarization can be found in these films over a waiting time of 1 × 105 s in the retain test. It is proposed that the high degree of 111 orientation of the PTZT films induced by LSMO is responsible for the excellent performance of the PTZT film capacitors. These studies demonstrated that the PTZT films with the LSMO buffer layer look very promising for ferroelectric memory applications and the developed techniques are very compatible with semiconductor technology.