STUDY OF 3C-SIC CRYSTAL DEFECTS BY MICROBEAM CHANNELING METHODS

SiC single crystals (zinc-blende structure) were epitaxially grown on (100) Si crystal substrates by chemical vapor deposition. It is known that its electrical characteristics and surface morphology are very se nsitive to the CVD conditions. Three-dimensional microstructures of a crystal with epitaxially grown 3C-SiC layer were analyzed with channel ing scanning transmission ion microscopy (CSTIM). By using a 2.0 MeV p roton microbeam, of 1 mu m diameter and focusing angle 0.2 degrees, ch anneling contrast maps along the [100] crystal axis were obtained. Sev eral anomalously grown regions with mean diameters of either 10 mu m o r less than 5 mu m were observed with CSTIM for a self-supported thin 3C-SiC epilayer. Since dE/dx of channeling protons differ from that of nonchanneling protons, it was found that the nonchanneling regions ha ve columnar structures with different lengths and project from the sur face.