The defects generated inSiO2during irradiation with energetic (10 eV) photons were found to trap electrons at a level 3.1 eV below the oxide conduction band. The electron spin resonance data and the behavior upon hydrogen passivation indicate that the optically active state may be ascribed to a H-complexed oxygen vacancy inSiO2.The observed injection of electrons to these traps from Si advances the revealed defects as the possible origin of the degradation-induced electrical conduction of thinSiO2layers. ©1997 American Institute of Physics.