Effect of LaNiO3 top electrode on the resistance of Pb(Zr,Ti)O3 ferroelectric capacitor to hydrogen damage and fatigue

The polarization hysteresis characteristics of Pb(Zi,Ti)O-3 (PZT) capacitors with a Pt top electrode are degraded by annealing in a hydrogen-containing environment due to the catalytic effect of Pt. This degradation can be avoided by adopting an LaNiO3 (LNO) conductive film as a top electrode. The LNO film does not act as a catalyst for the dissociation of hydrogen molecules and it is also a good diffusion barrier to the hydrogen molecules. The resistance of the LNO film to hydrogen degradation is further enhanced by inserting a thin Pt layer between the LNO and PZT films due to the blocking ability of Pt against the out-diffusion of the Pb component from the PZT film. The polarization characteristics of LNO/Pt/PZT/Pt capacitors are well preserved after hydrogen annealing even at 400degreesC for 30 min. The use of the LNO film as a top electrode also has a significant effect on improving the fatigue property of PZT capacitors.