Photon-Induced Oxygen Loss in Thin SiO2Films

Ultraviolet irradiation of thin (∼ 15-Å) laser-grown Si${\mathrm{O}}_2$ in vacuum renders the oxide unstable and it desorbs when heated to around 760 K. From electron spin resonance and Auger spectroscopy we conclude that irradiation produces a dense defect structure leaving thin films oxygen deficient, $\mathrm{Si}{\mathrm{O}}_x$ ($x<\mathrm{}2\mathrm{}$). Observed Auger-spectra modifications then correlate well with calculated band structures for defects in Si${\mathrm{O}}_2$.