Effects of the interfacial layer on electrical characteristics of Al_2O_3/TiO_2/Al_2O_3 thin films for gate dielectrics

摘要

Effects of thermal annealing on the electrical properties of Al_2O_3/TiO_2/Al_2O_3 (ATA) dielectric thin films prepared by atomic layer deposition are investigated. The structural properties and chemical states in the interfacial layer are analyzed with varying the annealing temperature. The dielectric constant and leakage current are affected by the formation of Al_2O_3-TiO_2 composite and interfacial layer including SiO_x in the interface by the annealing. The transformation of interfacial layer at the interface of the ATA/Si substrate due to the annealing is a critical point to apply ATA thin films as gate dielectric layers.