New approach to growth of high-quality GaAs layers on Si substrates

Abstract

GaAs films were grown by molecular beam epitaxy (MBE) on Si (100) substrates using a two-step growth process of a 300 °C GaAs buffer layer followed by a 600 °C device layer. The films were examined by Rutherford backscattering and x-ray diffraction methods. A significant reduction in the defect density near the GaAs/Si interface and in the bulk of these films was observed when the buffer layer was deposited by alternately supplying Ga atoms and As4 molecules to the substrate, rather than applying conventional MBE. Possible reasons for this reduction of crystal defects are discussed.