Influence of a nanoporous silicon layer on the practical implementation and specific features of the epitaxial growth of GaN layers on SiC/$por$-Si/$c$-Si templates

A set of structural and spectroscopic methods of diagnostics is used to study the influence of a nanoporous silicon ($por$-Si) transition layer on the practical implementation and specific features of growth of GaN layers on SiC/$por$-Si/$c$-Si templates by molecular-beam epitaxy with the plasma activation of nitrogen. It is shown that a $por$-Si transition layer introduced into a template, in which a 3$C$-SiC layer is created by the method of atom substitution, offers unquestionable advantages over standard silicon substrates. Specifically, such an approach makes it possible to lower the level of stresses in the crystal lattice of the epitaxial GaN layer by about 90% and to reduce the fraction of vertical dislocations in the GaN layer. The GaN layer is grown on the surface of the SiC layer, which in turn is on the surface of the SiC/$por$-Si/$c$-Si template. It is found for the first time that the use of the SiC/$por$-Si/$c$-Si template brings about the formation of a qualitatively more uniform GaN layer free of visible extended defects.