Comparative anomalous small-angle x-ray scattering study of hotwire and plasma grown amorphous silicon-germanium alloys

The nanostructure of hydrogenated amorphous silicon-germanium alloys, a-Si1-xGex:H, prepared by the hotwire deposition technique (x=0.06-0.79) and by the plasma enhanced chemical vapor deposition technique (x=0 and 0.50) was analyzed by anomalous small-angle x-ray scattering experiments. For all alloys with x >0 the Ge component was found to be inhomogeneously distributed with correlation lengths of about 1 nm. A systematic increase of the separated scattering was found due to the increasing Ge concentration. The different preparation techniques show significant differences in the Ge distribution. (C) 2001 American Institute of Physics.