Total reflection x-ray photoelectron spectroscopy

We have measured x-ray photoelectron spectra of Au/Si wafer and SiO2/Si wafer using grazing incidence x-rays. The spectral profiles have drastically changed backgrounds with the change of angle of incidence just above and below the critical angle of x-ray total reflection. The background intensity was reduced to less than 1/2 when the glancing angle of the incident x-ray beam was just below the critical angle compared with just above the critical angle. The excitation x-rays were those from a synchrotron radiation source. Four incident x-ray energies were selected between 2000 and 3000 eV. The electron energy analyzer was a concentric hemisphere analyzer. The samples were a Si wafer as received and a Au evaporated Si wafer. The XPS signal from an oxide layer on the Si wafer surface was observed to be enhanced when the incident x-rays were totally reflected.