Step-by-step growth of an epitaxial Si₄O₅N₃ single layer on SiC(0001) in ultrahigh vacuum

An epitaxial single Si₄O₅N₃ layer was formed on a SiC(0001) surface using a step-by-step growth method in an ultrahigh vacuum condition. First, a silicon adsorbed SiC(0001) surface was prepared. The surface was then exposed to NO gas at 950 °C in order to form a Si₂ON₃ layer. Silicon was deposited on this surface and annealed to adjust the amount of adsorbed Si atoms. Finally, the surface was oxidized at 800 °C. The formation of a Si₄O₅N₃ layer was confirmed by low-energy electron diffraction analysis, Auger electron spectroscopy, and scanning tunneling microscopy. Using this procedure, we were able to suppress the growth of graphite-like clusters on the surface, although silicate-like clusters still remained.