Electron beam induced optical and electronical properties of SiO2

Ionizing radiation in dielectric and optically transparent silica as well as thin SiO2 layers produces defect luminescence as well as charge storage. A comparison of different excitation-relaxation processes like cathodoluminescence, charge injection and trapping, secondary electron field emission, and exoelectron emission leads to a generally similar excitation dose behaviour described by an electron beam saturation dose of 0.01--0.1 C/cm(2). This suggests a correlation of these four electron excitation mechanisms likely related to the same kind of defect in glassy SiO2, the 2-fold-coordinated silicon =Si: centre with typical electronic singlet-singlet and singlet-triplet transitions according the Skuja model. (C) 2000 Elsevier Science S.A. All rights reserved.