Diffraction and X-ray reflection at grazing incidence. Possibilities of studying multilayer thin-film structures

A method of subsurface layer structure investigation based on the measurement of diffraction as well as reflection in grazing-incidence geometry is presented. A specific feature of this method is that the incident beam is nearly parallel to the surface and suffers diffraction along with reflection, which leads to a significant decrease of the radiation penetration depth. As a result, the above methods turn out to be rather sensitive to the structure of thin (1-100 nm) crystal layers near the surface. The effect of an amorphous layer on the angular dependence of grazing X-ray scattering is studied. The theoretical part of the work is based on the well known Parratt formulae for the reflection coefficient and also on the modified two-wave diffraction theory.