Total reflection X-ray topography for the observation of misfit dislocation strain at the surface of a Si/Ge-Si heterostructure.

Synchrotron X-Ray Topography has been used in Total Reflection Topography (TRT) mode to observe strain induced surface bumps due to the presence of underlying misfit dislocations in strained layer SiGe on Si epitaxial heterostructures. In these experiments the x-rays approached the sample surfaces at grazing incident angles below the total external reflection critical angles for a number of reflections and hence surface strain features nominally less than a few tens of Ångstroms from the sample surface have been observed. These are similar to the surface bumpiness observed by Atomic Force Microscopy, albeit on a much larger lateral length scale. The fact that TRT mode images were taken was confirmed by the observation of clear and conventional back reflection topographic images of misfit dislocations in all samples when the grazing incidence angle became greater than the critical angle.

Grazing incidence synchrotron X-ray topography as a tool for denuded zone studies of silicon wafers.

Reflection topographs of annealed Czochralski-grown silicon wafers are made with synchrotron white beam radiation at grazing angles of 0.2 degree to 3 degree. Information on the uniformity of the denuded zone is obtained from a number of grazing incidence topographs, which according to calculations turn out to be almost completely monochromatic having a negligible harmonic content. The calculated penetration depth ranges from 1 to 100 µm depending on the grazing angle and reflection used. The grazing incidence topographs are compared with section topographs of the same samples.