The Effects of Annealing Ambient on the Characteristics of La[sub 2]O[sub 3] Films Deposited by RPALD

Abstract

We investigated the effects of different annealing ambients on the physical and electrical properties of lanthanum oxide (La2 O3) films grown by remote plasma atomic layer deposition (RPALD). Rapid thermal annealing was carried out at 800°C for 1 min in O2, N 2, and vacuum ambients. The chemical bonding states at the interface between the Si substrate and the La2 O3 films were analyzed using X-ray photoemission spectroscopy. The amount of OH groups that were absorbed from air in the La2 O3 films decreased after annealing at 800°C. La2 O3 and its interfacial layer were affected by the different annealing ambients. The electrical properties of the La2 O3 films were studied using capacitance-voltage and current-voltage plots. Without annealing treatment, the flatband voltage (VFB) for the La2 O3 film was measured to be -0.31 eV. When La2 O3 was annealed at 800°C in N2 and O2 ambients, positive shifts of 0.16 and 0.64 eV, respectively, were observed. © 2010 The Electrochemical Society.