Growth and surface structure analysis of a new SiON single layer on SiC(0001)

A new silicon oxynitride layer was formed on a 6H-SiC(0001) surface by a nitrogen oxide treatment. The atomic structure of this single layer on the SiC(0001) substrate was determined by means of low-energy electron diffraction (LEED) analysis. The surface layer has a (3×3) R30° periodicity. Its LEED I(E) spectra are different from those of the previously reported silicon oxynitride layer which has a Si4O5N3 composition [Phys. Rev. Lett. 98 (2007) 136105]. The best-fit structure has a single layer of Si2ON3 composition terminated by O bridges. The Si-N layer of the determined structure has the same structure as that in the Si4O5N3 surface. The obtained Si2O3 structure would be useful for preparing an ideal SiC-insulator interfaces with a low interfacial density of states.