We present a study on amorphous SiO/SiO2 superlattice using grazing incidence small-angle X-ray scattering (GISAXS). Amorphous SiO/SiO2 superlattices were prepared by high vacuum evaporation of 3 nm thin films of SiO and SiO2 (10 layers each) on Si(100) substrate. After the evaporation, samples were annealed at 1100 degrees C for 1 h in vacuum, yielding Si nanocrystals formation. Using a Guinier approximation, the shape and the size of the crystals were obtained. (c) 2005 Elsevier B.V. All rights reserved.