In situ RHEED analysis of epitaxial Gd2O3 thin films grown on Si (001)

Epitaxial Gd2O3 thin films were successfully grown on Si (001) substrates using a two-step approach by laser molecular-beam epitaxy. At the first step, a ∝0.8 nm thin layer was deposited at the temperature of 200 circle C as the buffer layer. Then the substrate temperature was increased to 650 circle C and in situ annealing for 5 min, and a second Gd2O3 layer with a desired thickness was deposited. The whole growth process is monitored by in situ reflection high-energy electron diffraction (RHEED). In situ RHEED analysis of the growing film has revealed that the first Gd2O3 layer deposition and in situ annealing are the critical processes for the epitaxial growth of Gd2O3 film. The Gd2O3 film has a monoclinic phase characterized by X-ray diffraction. The high-resolution transmission electron microscopy image showed all the Gd2O3 layers have a little bending because of the stress. In addition, a 5-6 nm amorphous interfacial layer between the Gd2O3 film and Si substrate is due to the in situ high temperature annealing for a long time. The successful Gd2O3/Si epitaxial growth predicted a possibility to develop the new functional microelectronics devices. (orig.)