Graphitic features on SiC surface following oxidation and etching using surface enhanced Raman spectroscopy

Graphitic features are detected on 4H-SiC surface following oxidation and etching using surface enhanced Raman spectroscopy (SERS). The electronic state of the carbon is sp(2) on both the Si- and C-faces of 4H-SiC. The structures of the carbon clusters consist of two-dimensional graphitic flakes less than 2 nm and one-dimensional polyenes. The degree of graphitization on the C-face SiC is higher than those on the Si-face SiC. This study provides experimental evidence for carbon clusters existing on SiC surfaces following oxidation at atmospheric pressure and demonstrates that SERS is an effective technique to probe low concentration species on the SiC surface. (C) 2004 American Institute of Physics.