Surface modification of CaF2 on Si(111) by low-energy electron beam for over growth of GaAs films

Abstract
Surface modifications of epitaxial CaF2 on Si(111) by low‐energy electron beam, in order to get modified surfaces with reduced damage on which high quality GaAs films could be grown, were studied. By using x‐ray photoelectron spectroscopy measurements, it was found that it is possible to modify the surface of CaF2(111) even though the energy of the electron beam was as low as ∼10 eV. The generation of defects in bulk CaF2 and the diffusion of As were found at an energy of 305 eV, whereas no such evidence of defect, but rather, a stable adsorption of As on the surface of CaF2, was observed at an energy of 40 eV.