Color cathodoluminescence-scanning electron microscopy study of the 4H-SiC heteroepitaxial layers grown by sublimation ''sandwich method''

The color cathodoluminescence scanning electron microscopy (CCL-SEM) technique was used for the study of the 4H-SiC epitaxial layers grown by sublimation ''sandwich method'' on the 6H- or 21R substrates. Elements of the BIY group were introduced for polytype transformations. The method makes it possible to control the polytype in thin layers (0.1-2 mu m). The effect of supersaturation and the growth rate on 4H polytype formation have been studied. It was shown that the probability of polytype transformation depends on the configuration of the substrate surface. At low supersaturation, 4H polytype nuclei arise predominantly on projected areas of the (000 1)C substrate surface, which had no growth centers such as screw dislocations.