Structural and morphological peculiarities of the epitaxial layers and monocrystals of silicon carbide highly doped by nitrogen

A qualitative dependence of polytype structures 6H, 15R, and 3C on the partial pressure of nitrogen in the interval 4 to 760 Torr is obtained by optical and X-ray studies of SiC epitaxial layers, grown by recrystallization in the gaseous phase at 1900 to 2300°C. The morphological peculiarities of β-SiC epitaxial layers, grown on the (0001) and (0001) faces of the α-SiC substrate are determined. The strained regions of the α-SiC monocrystals, due to inhomogeneous nitrogen-doping, are established by optical and X-ray methods. The effect of nitrogen on the polytype stability of SiC is the basis of the discussion of the experimental data.