Improved ferroelectric property of LaNiO_3/Pb(Zr_(0.2)Ti_(0.8))O_3/LaNiO_3 capacitors prepared by chemical solution deposition on platinized silicon

摘要

We report a technique to prepare top and bottom oxide electrodes of LaNiO_3 (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 LaNiO_3 film to serve as protective masks during etching of the uncovered LaNiO_3 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 21.4 μC/cm~2, 71 and 81.5 kV/cm respectively at 5 V. The leakage current density for the Pt/LNO/PZT/LNO/Pt structure is about 1.38 x 10~(-6) A/cm~2 at 5 V, which is lower than that of PZT deposited on Pt electrode. After 10~9 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.