The Effects of Annealing Ambient on the Characteristics of La2O3 Films Deposited by RPALD

Abstract

We investigated the effects of different annealing ambients on the physical and electrical properties of lanthanum oxide (La2O3) films grown by remote plasma atomic layer deposition (RPALD). Rapid thermal annealing was carried out at 800 degrees C for 1 min in O-2, N-2, and vacuum ambients. The chemical bonding states at the interface between the Si substrate and the La2O3 films were analyzed using X-ray photoemission spectroscopy. The amount of OH groups that were absorbed from air in the La2O3 films decreased after annealing at 800 degrees C. La2O3 and its interfacial layer were affected by the different annealing ambients. The electrical properties of the La2O3 films were studied using capacitance-voltage and current-voltage plots. Without annealing treatment, the flatband voltage (V-FB) for the La2O3 film was measured to be -0.31 eV. When La2O3 was annealed at 800 degrees C in N-2 and O-2 ambients, positive shifts of 0.16 and 0.64 eV, respectively, were observed.