Improved ferroelectric property of LaNiO3∕Pb(Zr0.2Ti0.8)O3∕LaNiO3 capacitors prepared by chemical solution deposition on platinized silicon

Abstract

We report a technique to prepare top and bottom oxide electrodes of LaNiO3 (LNO) for lead zirconate titanate (PZT) films using a chemical solution deposition. LNO/PZT/LNO sandwich structures were prepared on platinized silicon by spin coating combined with rapid thermal annealing. Pt dots were sputtered on top of LaNiO3 film to serve as protective masks during etching of the uncovered LaNiO3 layer using dilute hydrochloric acid. For comparison, Pt/PZT/Pt capacitors were also prepared using the same processing conditions. Electrical measurements were carried out on both Pt/LNO/PZT/LNO/Pt and Pt/PZT/Pt structures. The remnant polarizations and coercive fields for these two capacitors are 17.4 and 21.4μC∕cm2, 71 and 81.5kV∕cm respectively at 5V. The leakage current density for the Pt/LNO/PZT/LNO/Pt structure is about 1.38×10−6A∕cm2 at 5V, which is lower than that of PZT deposited on Pt electrode. After 109 bipolar switching cycles, no significant change in remnant polarization was observed in the Pt/LNO/PZT/LNO/Pt capacitor, in comparison to the Pt/PZT/Pt capacitor which lost more than 50% of its original remnant polarization.

Microstructure and ferroelectric properties of BaTiO3 films on LaNiO3 buffer layers by rf sputtering

“…In the past, extensive efforts have been made on preparing ferroelectric thin films on Pt metallic electrodes, but the ferroelectric films have been easily fatigue degraded and further more it was difficult to grow highly (1 0 0)-oriented BTO films directly on Pt-coated silicon (Si) substrate. Recent researches on ferroelectric films preparation revealed that some perovskite-related metallic oxides, such as YB 2 Cu 3 O 7Àx (YBCO), La 0.5 Sr 0.5 CoO 3 (LSCO), SrRuO 3 (SRO) and LaNiO 3 (LNO), could be employed as electrodes not only for the great improvement of fatigue and aging of ferroelectric films but also help to form certain orientations [5].…”

Influence of LaNiO3 bottom electrode on the structural and physical properties of ferroelectric capacitors

“…Tel. : +86 312 5977033; fax: +86 312 5011174. one of the most promising materials for ferroelectric electrodes [13]. Although many results related to LNO electrodes of PZT capacitors have been published [14,15], impact of LNO bottom electrodes grown at various temperatures on the structural and physical properties of PZT capacitors is still not clear.…”

Low Fatigue in Epitaxial Pb(Zr0.2Ti0.8)O3 on Si Substrates with LaNiO3 Electrodes by RF Sputtering

“…It was reported that PZT deposited on Pt electrodes started to lose remanent polarization dramatically after 10 6 cycles. 6 More recent research work found that the fatigue problem could be improved up to 10 11 cycles by using conductive oxides electrodes such as RuO 2 , SrRuO 3 , IrO 2 , La 1Àx Sr x CoO 3 (LSCO), YBa 2 Cu 3 O 7Àx , and LaNiO 3 . 7-11 Among those conductive oxides, LaNiO 3 is widely used as a bottom electrode material for ferroelectric thin-film capacitors because of its good electrical conductivity and low processing temperature.…”