X-RAY-EXAMINATION OF SIC MONOCRYSTALS

Five X-ray methods (Lang topography, one-crystal rocking curves with s can-step registration, two-crystal diffractometry, Bond measurements, detection of double reflections caused by Umweganregung) are used for real structure examination of SiC bulk crystals. The most important re sult is that Bond measurements show only relatively weak changes of th e lattice constants between measuring points of a given sample (deviat ions lower than 10 ppm for the lattice constant c). However, the other diagnostic techniques show greater lattice distortions. The differenc es in the lattice constants between different samples of the same poly type may reach up to 100 ppm.