The influence of reconstruction on epitaxial growth: Ge on Si(100)-(2 × 1) and Si(111)-(7 × 7)

The initial stages of interface formation in the Si(100)-(2 × 1)/Ge and Si(111)-(7 × 7)/Ge systems are investigated using Rutherford Backscattering/Channeling techniques supported by Auger electron spectroscopy and low energy electron diffraction (LEED). For deposition at 300 K the Ge forms a sharp but highly disordered overlayer with no indication of islanding or indiffusion. The Ge deposition at 300 K relieves the reconstruction of the Si(100) but not of the Si(111) surface. This difference is interpreted in terms of structural models for these two surfaces. The surface reordering is investigated as a function of deposition temperature and predeposited deuterium coverage. A large body of data supports the model of a temperature-activated chemisorption-induced reordering in which each layer of Ge relieves each layer of Si reconstruction.