Development of an Atomic Oxygen Source for Thin Oxide Film Formation

Abstract

ABSTRACTAtomic oxygen promotes the oxidation of thin films. The authors developed a silent discharge type atomic oxygen source for thin oxide film formation. The atomic oxygen source consists of a quartz discharge tube and two cylindrical electrodes that are attached to the outside wall of the tube. The atomic oxygen concentration is estimated to be 3%.The atomic oxygen source was installed in an ICB (Ionized Cluster Beam) apparatus and applied to the formation of Er-Ba-Cu-0 thin films. By introducing the atomic oxygen during deposition, a film showing superconductivity at 81K was obtained when the substrate temperature was 570ºC. Also the substrate temperature to obtain a film showing superconductivity at 77K was estimated to be 50 °C lower than that for obtaining superconducting film formation in an atmosphere of 6% ozone. The atomic oxygen source was also applied to SrTiO3 thin film formation. Electrical properties of this film were examined and compared with those of films prepared in an atmosphere of 6% ozone. The dielectric constant of SrTiO3 film was improved from 60 to 180 by introducing atomic oxygen instead of 6% ozone. Therefore the atomic oxygen source was proven to be advantageous for thin oxide film formation.