Effects of Pt/SrRuO3 top electrodes on ferroelectric properties of epitaxial (Pb, La)(Zr, Ti)O-3 thin films

Epitaxially c-axis oriented PLZT films with the composition (Pb0.925La0.075)(Zr0.4Ti0.6)O-3 were deposited on Pt/MgO(100) substrate by rf-magnetron sputtering using a compacted powder target with the composition (0.8PLZT+0.2PbO). Pt/SrRuO3(SRO)/PLZT/Pt capacitors were successfully fabricated by forming Pt/SRO top electrodes onto PLZT films.`The 206-nm-thick PLZT films with layered Pt/SRO top electrodes exhibited a slightly high leakage current at a low electric field: compared with PLZT films with the same thickness and a single Pt top electrode. The values of switchable polarization after 10(10) cycles for Pt/PLZT/Pt capacitors decreased up to around 17% of their initial values, whereas the switchable polarization for Pt/SRO/PLZT/Pt capacitors hardly exhibited any fatigue degradation due to polarization reversal. The layered Pt/SRO is useful as a top-electrode material for fabricating the low leakage and high endurance ferroelectric capacitors.