Channeled ion assisted epitaxial growth of Ge on thin Si substrates

Germanium films were vapour-deposited on thin self-supporting Si substrates of about 1 μm in thickness. During deposition, the substrates were irradiated on the backsurface by a C ⁺ beam with energies between 0.6 and 1.8 MeV in a <100> channeling condition. The substrate was heated up to about 400°C only by the beam of intensity lower than 2 μA/cm ². Both backward and forward scattering spectrometries combined with the channeling technique were used as a monitor for alignment of the substrate to the <100> axial channeling condition and characterization of epitaxial Ge films. Heteroepitaxial growth of Ge films was observed for substrate temperature of about 350°C and incident energies of 0.6-1.8 MeV. The results showed that the energy of the assist beam remarkably affects the crystalline quality of Ge film and Si substrate, as well as the morphology of grown Ge.