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Doping processes of silicon carbide crystals with scandium are investigated. It is shown that the scandium solubility in SiC is limited within the 1800 to 2600°C temperature range and amounts to (2 to 3) × 1017 cm−3. On doping silicon carbide crystals with scandium the VLS growth mechanism is possible. The luminescence spectra of the crystals are studied. It is found that nitrogen actively affects the luminescence intensity of silicon carbide doped with scandium. The depth of the radiative recombination centre in SiC (Sc) which is acceptor like is found to be 0.24 eV. [Russian Text Ignored].

The question of the interrelation of synthesis conditions with the energy distribution in photoluminescence spectra is studied for SiC epitaxial layers of 4H and 6H polytypes grown in the presence of rare-earth metals Tb and Sc. Marked differences in the energy distribution in the observed spectra indicate that in the process of growth from gas and liquid phases different emission centres are formed. It is found that the position of the maxima of the high temperature photoluminescence bands for 6H-SiC epilayers grown from the gas phase in the presence of Tb coincides with that for 6H-SiC layers in which boron is introduced by diffusion. [Russian text Ignored]

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. [Russian Text Ignored]

Recombination centres in luminescent crystals n-SiC(6H) doped with nitrogen and compensated with boron during the diffusion process are investigated by photocapacitance method. Boron diffusion results in appearance of a deep centre which is able to capture holes effectively. The ionization energy of this centre ET = (0.4 ± 0.02) eV coincides with the boron ionization energy in p-SiC(6H): B crystals and the spectral dependence of photoionization cross-section qp is similar to the spectral dependence of absorption near the long-wave edge of the absorption band of these crystals. But such centre is not observed in n-SiC(6H): B original samples in spite of the large quantity of boron in them. Based on these facts the conclusion can be made that boron with respect to the capture of the holes may be either in active or in bound states depending on the method of doping. This results in different efficiency of photoluminescence of crystals doped with boron in the growth and diffusion processes. [Russian Text Ignored].

The kinetics of silicon carbide synthesis plays an important part in the formation of polytypes during the growth of crystals and epitaxial layers. The results obtained permit to develop a technique of plotting kinetic phase diagrams with the polytypes shown for silicon carbide. In particular, these phase diagrams accomodate quite well the conditions of production (rather high growth rates at comparatively low temperatures of growing) of crystals and epitaxial layers of β-SiC from solutions in silicon melts and at decomposition in hydrogen of methyl-trichlorosilane and other silicon-and carbon-containing organic compounds. [Russian text Ignored.]