GISAXS study of Si nanoclusters in SiO/SiO2 layers

We present a study on amorphous SiO/SiO2 superlattice using grazing-incidence small-angle X-ray scattering (GISAXS). Such nanostructured material might be of great interest for photovoltaic conversion and optoelectronics. Amorphous SiO/SiO2 superlattices were prepared by magnetron sputtering of thin SiO and SiO2 films (20 layers each) on Si (1 0 0) substrate. Rotation of the Si substrate during evaporation ensures homogeneity of the films over the whole substrate. After the evaporation, the samples were annealed at 1100 °C for 1 h in vacuum. The analysis of the 2-D GISAXS pattern has shown that Si nanocrystals are formed in the remaining SiO2 films in the annealed samples. From the 2-D GISAXS pattern, their shape, size and inter-particle distance are determined.