Materials Science Forum, Vol.457-460, 339-342, 2004
Structural defects in SiC crystals investigated by high energy x-ray diffraction
High energy x-ray diffraction (up to 300 keV) has been used to analyse structural defects in an as grown SiC boule with a diameter of 55 nun, a thickness of 20 mm and in a 2 inch wafer. The crystals are 6H SiC grown by PVT method. In the wafer numerous grains can be identified and localised with a mosaicity in the order of 0.05degrees, whereas the whole wafer shows a mosaic spread of around 0.1degrees. The bulk crystal shows a pronounced domain structure and a bending in the lattice plane orientation. The local reflection broadening is between 0.2degrees and 2degrees, while the tilts of the lattice planes over the entire wafer are between 2 and 6degrees (2theta-values).