Enhanced fatigue and retention properties of Pb(Ta0.05Zr0.48Ti0.47)O3 films using La0.25Sr0.75CoO3 top and bottom electrodes

Abstract

Ferroelectric perovskite Pb(Ta0.05Zr0.48Ti0.47)O3 thin-film capacitors having LaxSr1−xCoO3 bottom and top electrodes have been prepared on Pt/TiO2/SiO2/Si(001) substrates by pulsed-laser deposition. It is found that La0.25Sr0.75CoO3 bottom electrodes with cubic structure strongly promote the formation of (001) texture of PTZT films and improve the fatigue and retention properties of the capacitors. The polarization of the La0.25Sr0.75CoO3/Pb(Ta0.05Zr0.48Ti0.47)O3/La0.25Sr0.75CoO3 capacitors with a Pb(Ta0.05Zr0.48Ti0.47)O3 thickness of 400 nm were subjected to no degradation after 1×1010 switching cycles at an applied voltage 5 V with a frequency of 1 MHz. The capacitor retains more than 92.6% of its polarization after a retention time up to 105 s. The possible microstructural background responsible for the excellent fatigue and retention properties was discussed.