ABSTRACTFor high-power device applications SiC has better physical and electronic properties than the traditional semiconductor materials Si and GaAs. In this work, structural defects of 4H SiC wafers have been studied and partly compared with results from a previous study of 6H material. Optical microscopy, scanning electron microscopy, high-resolution X-ray diffraction and synchrotron X-ray topography were used for structural studies of 4H SiC.Optical micrographs show micropipes and larger specific defects - tubes and cracks. X-ray rocking curve peaks are broad and split revealing the mosaicity of the material. Synchrotron X-ray topographs show areas having a large number of defects, images of cracks and micropipes, and misorientated regions close to the micropipes.
