Ageing of Thin-Film Capacitor Structures Based on PZT

Thin-film Pt/PZT/Ir(Ti/SiO/Si) and Ir/PZT/PTO/Ir(Ti/SiO2/Si) capacitors, as-grown and after ageing, are investigated. A comprehensive study based on the Auger spectroscopy and measurement of electrical and ferroelectrical characteristics is performed. Ageing results in increasing of the oxygen content in PZT, broadening of interfaces owing to formation of metal oxides, diffusion of Pb and Ti towards the top electrode along the grain boundaries, and diffusion of Ti into PZT grain. These processes induce decreasing of the structure capacitance, healing of the interface traps, enhance leakage and dielectric loss.