Effect of postdeposition annealing on the structural and electrical properties of thin Dy2TiO5 dielectrics

This paper describes the effect of postdeposition annealing on the structural and electrical characteristics of high-k Dy2TiO5 dielectric films deposited on Si (100) through reactive cosputtering. We used X-ray diffraction, X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and atomic force microscopy to investigate the structural and morphological features of these films after they had been subjected to annealing at different temperatures. The Dy2TiO5 dielectrics annealed at 800 deg. C exhibited excellent electrical properties such as high capacitance value, small density of interface state, almost no hysteresis voltage, and low leakage current. This phenomenon is attributed to a rather well-crystallized Dy2TiO5 structure and the reduction of the interfacial layer at oxide/Si interface. This film also shows almost negligible charge trapping under high constant voltage stress.