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In this paper, the authors studied anatase TiO2 films, fabricated by using atomic layer deposition and postdeposition annealing (PDA). The as-grown TiO2 films were of high purity; the carbon and nitrogen contents were within the x-ray photoelectron spectroscopy detection limit of 3–5 at. %. The anatase TiO2 film fabricated by PDA at 500 °C in O2 had a very high dielectric constant of >30 and was of high quality because it exhibited no hysteresis at its flatband voltage (Vfb) and contained negligible defect charge. The positive Vfb shift of anatase TiO2 (0.08 V), caused by the bottom interface dipole at a TiO2/SiO2 interface, was much smaller than those of Al2O3 (0.72 V) and HfO2 (0.29 V). However, the maximum Vfb change of the anatase TiO2 was greater than those of HfO2 and HfSiOx because the TiO2 contained more oxygen than the other materials.

Density functional calculations are performed for lanthanum-oxide clusters in order to study the local dielectric properties of such clusters using the dielectric constant defined at local points. An increase in coordination number brings about an increase in electron population on the central lanthanum atom, leading to an increase in the local dielectric constant.