Dynamic change in the surface and layer structures during epitaxial growthof Si on a Si(111)-7X7 surface

In order to investigate the dynamic process during growth of a Si layer on the Si(111)-7 X 7 surface held at 380 degrees C, the rocking curve of refle ction high-energy electron diffraction (RHEED) is continuously measured at 0.5 degrees to 6 degrees at intervals of 0.05 degrees to the glancing angle of the incident electron beam which takes 18 sec. At the initial growth st age, the multilayer islands are grown on the native 7 X 7 surface with broa der Bragg peaks in the rocking curve than those from the native surface. Th e sharpness of the Bragg peak is subsequently recovered after the thickness of the Si layer reaches 3 BL (1 BL = 0.31 nm), at which the growth transfo rms to layer-by-layer growth. The comparison of the measured rocking curve with the calculated one based on the dynamical theory of RHEED intensity is also performed by optimizing each atomic position in the growing layer so as to minimize the difference between both curves. The space of the double layer of the (111) plane in the multilayer islands expands and is restored to the normal spacing after the growth mode transforms to the layer-by-laye r mode. The broadening of the Bragg peaks at the initial growth stage relat es to the rearrangement process of a stacking-fault layer in the 7 X 7 stru cture on the substrate surface.