Electrical properties of anatase TiO2 films by atomic layer deposition and low annealing temperature

Abstract

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.