Effects of hybrid structure top electrodes of pzt capacitors on hydrogen-induced damage

We propose that Ti/Ir hybrid structure top electrodes improve resistance against hydrogen-induced damage. As the ratio of Ti/Ir increases, the capacitors show enhanced endurance against hydrogen damage. Especially, PZT (350 nm) capacitors with Ti(80 nm)/Ir(20 nm) hybrid top electrodes show only a 16 % decrease in nonvolatile polarization under ± 7 V while the nonvolatile polarization of ferroelectric capacitors with Ir top electrodes is reduced by 62.1 % after forming gas annealing at 250 °C for 10 min. The XPS analysis shows that the ferroelectric characteristics of PZT thin film capacitors with the catalytic top electrodes (Ir, Pt) are degraded by destruction of Pb-O bond into metallic Pb due to hydrogen annealing.