X-ray reflectivity of self-assembled structures in SiGe multilayers and comparison with atomic force microscopy

We have studied the interface morphology of SiGe/Si multilayers by means of specular and nonspecular x-ray reflectivity under grazing incidence. The s amples were grown by molecular beam epitaxy on silicon substrates with (001 ) surface orientation and with different directions of the surface misorien tation. X-ray reflectivity measurements in different azimuths are compared to data from atomic force microscopy, which are used to simulate the x-ray experiments. With this combination of experimental techniques we have deter mined the structural properties, in particular the ordering of different fe atures present at the sample surface and inside the multilayer at the SiGe/ Si layer interfaces. (C) 2001 American Institute of Physics.