Auger electron peaks of Cu in XPS

Intensities of photoelectron and photo-excited Auger electron peaks observed in X-ray photoelectron spectroscopy of copper have been analyzed using a background optimization formalism. The relative intensities of L2, 3MM peaks are proportional to those predicted by Auger transition probabilities. However, their absolute intensities are stronger than those of holes created by 2p photoemission. Measurement by monochromatic X-ray photoelectron spectroscopy indicates that there is a contribution from a 2s hole by Coster-Kronig transition. Moreover, a spectrum of a conventional (non-monochromatic) source suggests additional 2s and 2p holes by the accompanying Bremsstrahlung.