X-ray investigations of MBE-grown heteroepitaxial SiC layers on 6H-SiC substrates

3C-SiC thin films have been investigated by means of high resolution X-ray diffraction techniques (omega/2 Theta-scan, omega-scan) and X-ray topograph y. The SiC films were grown in a solid source molecular beam epitaxy (MBE) system on 6H-SiC substrate crystals. We investigate the lattice mismatch pa rallel and perpendicular to the [0001]-direction using the so-called recipr ocal space mapping technique. When 3C-SiC films were grown on 6H-SiC substr ates, double position boundaries (stacking sequence ACB instead of ABC) wer e frequently observed. For the visualization of this effect high resolution X-ray topographic measurements are investigated at 3C-SiC layers on 6H-SiC substrates, We find, that the domains of different stacking sequences are equally distributed in the 3C-SiC epilayer. This domains attain a size up t o approximately 200 x 200 mu m(2). (C) 1999 Elsevier Science S.A. All right s reserved.