In situ investigation of the island nucleation of Ge on Si(001) using x-ray scattering methods

摘要

The growth of Ge on Si(001) is investigated in situ at 500 and 600℃, combining grazing incidence diffraction, multiple wavelength anomalous diffraction, and small angle scattering. This allows probing simultaneously the island shape, strain state, composition, and the transition from wetting layer to island growth. At 500℃ no intermixing occurs. The wetting layer is found to decrease by one atomic layer at the onset of island nucleation. At 600℃ interdiffusion plays an important role in strain relaxation leading to a more stable wetting layer. Small angle scattering yields the island morphology and shows the transition from pyramids to multifacetted domes.