EXAFS AND SURFACE-EXAFS STUDIES IN THE SOFT-X-RAY REGION USING ELECTRON YIELD SPECTROSCOPY

This paper discusses extended x-ray absorption fine-structure (EXAFS) measurements using monochromatized synchrotron radiation in the 300-1000-eV range. EXAFS spectra were obtained by detecting the secondary electron yield from the sample. The electron yield technique is shown to exhibit several unique advantages over conventional absorption measurements. In particular, no thin-film samples are needed and, more important, measurements of surface phemonema become feasible. Results are presented for the N K-edge EXAFS in Si//3N//4 and for the O K-edge surface EXAFS of an oxygen monolayer on Ni (100).