EFFECTS OF Pt/SrRuO3 TOP ELECTRODES ON FERROELECTRIC PROPERTIES OF EPITAXIAL (Pb, La)(Zr, Ti)O3 THIN FILMS

Epitaxially c-axis oriented PLZT films with the composition (Pb0.925La0.075)(Zr0.4Ti0.6)O3 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 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 1010 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. 7 refs.