Threading dislocations, in thin Si layers of SIMOX samples, were studied by means of white or monochromatic X-ray diffraction topography in a transmission or reflection geometry. It was concluded that the symmetrical transmission geometry was most suitable for the present type of study. Dislocation images were visible in topographs, even though the Si layer thickness was very small when compared to the pendellösung distance. The dislocation contrast could be consistently explained by so-called interferometer-like or double-crystal diffractometry-like formation mechanisms. The former was controlled by local variations in the reciprocal lattice vector difference between the 2 parts of a bi-crystal. The second was controlled by variations in the effective misorientation. Contrast analyses revealed that the dislocations occurred in pairs, with anti-parallel Burgers vectors.

E.Prieur, M.Ohler, J.Härtwig: Physica Status Solidi A, 1996, 158[1], 19-34