Long-range behavior of the layer-by-layer growth in Si/Si(111)-7x7 homoepitaxy

Synchrotron x-ray scattering is used to reveal the long-range behavior of the layer-by-layer growth in Si/Si(111)-7x7. During the simultaneous nucleation of the first double bilayers, the long-range order of the 7x7 reconstruction diminishes continuously and disappears at the coverage of two bilayers. Based on the intensity variation at the 7x7 peak and at the specular reflection rod during the initial growth, the amount of the first three bilayers was obtained quantitatively. In addition, we measured the surface height fluctuation function in the steady-state layer-by-layer growth regime to reveal the morphology of the growth front.