Interfacial microstructure and electrical properties of PT/Al2O3/Si annealed at high temperatures

Pb1þxTiO3 (PT) thin films were deposited on Al2O3(10 nm)/Si using lead acetate trihydrate and titanium isopropoxide with the addition of glycerol (GL) chelating agent as precursors. It was found that perovskite PT phase can be well crystallized at a lower temperature of 600 8C and excellent memory properties are obtained. However, with increasing annealing temperature above 700 8C, charge-injection mode instead of ferroelectric behavior was detected. Cross-sectional TEM results illustrate that with an increase of annealing temperature and Pb content in the PT films, diffusion envelops and even composition separations were detected in the interface of PT/Al2O3/Si. It was believed that the degradation in the ferroelectric memory properties is strongly related to the change of microstructure and composition in the interface of PT/Al2O3/Si.