Surfactant mediated heteroepitaxial growth of Ge/Si(111) probed by X-ray photoelectron diffraction

X-ray photoelectron diffraction (XPD) is used as a tool to investigate the growth of Ge on Si(111) with and without surfactant (Sb) mediation. Structural information is extracted directly from the forward scattering maxima of recorded photoelectron diffraction patterns. The result of a quantitative analysis of the patterns taken for Ge layers of different coverage are used for a structural growth model of Ge on Si(111). Without Sb, a compression of the top Si and the first Ge double layers is found followed by a relaxation of the Ge structure. Under the presence of Sb an intermixed interface is formed followed by compressed Ge double layers and relaxed distances between double layers.