Structural and dielectric properties of epitaxial SrTiO₃ films grown directly on GaAs substrates by laser molecular beam epitaxy

Epitaxial SrTiO₃ films were grown on GaAs (001) substrates without any buffer layers using laser molecular beam epitaxy technique. The reflection high-energy electron diffraction observations have revealed that a layer-by-layer growth of SrTiO₃ was achieved at optimized deposition conditions. The crystalline orientation of the as-grown SrTiO₃ (001) films rotates 45° in plane with respect to the GaAs substrates. Atomic force microscope studies show that these films possess atomically flat surfaces. The dielectric properties of the heterostructure were also investigated. Our results have clearly demonstrated the practicality of integrating perovskite oxide thin films with GaAs substrates.