Detection of ultrathin amorphous layers by means of specular reflection under grazing-incidence diffraction conditions

The anomalous behaviour of the specular reflection under the condition of noncoplanar grazing-incidence x-ray diffraction have been revealed and studied. The phenomenon is analysed theoretically in a perfect crystal and in a crystal coated with an amorphous film. The high sensitivity to the presence and thickness of an several-nanometers thick amorphous films has been shown. Both the thickness and the density of the native oxide film coating the surface of a silicon single crystal were determined experimentally. (author)