Chemical-state-selective X-ray absorption spectroscopy by detecting bond-specific Auger electrons for SiO^sub 2^/SiC interface

Chemical-state-selective Si K-edge extended X-ray absorption fine structure (EXAFS) measurements of SiO2 and SiC are demonstrated by detecting bond-specific Auger electrons in SiC coated with a very thin SiO2 film. Differential-electron-yield (DEY) mode is used for the measurements. Each EXAFS spectrum may be subject to the following two spectrally overlapping influences: (i) the background spectrum formed by energy-losing SiC Auger electrons overlaps the SiO2 Auger peak, and (ii) the resonant SiO2 Auger peak overlaps the SiC Auger peak. The SiO2- and SiC-selective DEY–EXAFS spectra differ from each other and are similar to the spectra of bulk SiO2 and SiC, respectively, in the EXAFS regions, indicating that the two influences are negligible, and that this method can be considered valid for selection of chemical states.