Synchrotron radiation photoemission and X-ray photoelectron spectroscopy studies of argon ion etched SiO2 surfaces

Synchrotron radiation (SR) photoemission and angular-dependent X-ray photoelectron Spectroscopy (XPS) are used for studying phase changes induced by 2-keV argon ions on SiO surfaces. Evidence of damage is given for depths within 4-9 Å by selecting appropriate photon energies in SR experiments and low electron exit angles in XPS. SiO (x?1.2) suboxide phases form upon argon bombardment, and the SiO-to-undamaged SiO ratio varies considerably with varying surface sensitivity. It is shown that photoemission techniques possess a chemical sensitivity for the characterization of phase heterogeneities in bombarded SiO which is comparable with that offered by Auger (Si LVV) Spectroscopy, provided that a comparable surface sensitivity is achieved. © 1990.