Electron beam induced optical and electronical properties of SiO2

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