SELECTIVE THERMAL-DECOMPOSITION OF ULTRATHIN SILICON-OXIDE LAYERS INDUCED BY ELECTRON-STIMULATED OXYGEN DESORPTION

The mechanism of electron-beam-induced selective thermal decomposition of ultrathin oxide layers on Si surfaces was studied by scanning refl ection electron microscopy, Auger electron spectroscopy, and x-ray pho toelectron spectroscopy. We found that the change in the oxide layer c omposition caused by electron-stimulated oxygen desorption accounted f or the selective thermal decomposition, where nanometer-scale voids we re densely generated at a low heating temperature (720 degrees C). Thi s implies that oxygen desorption from the oxide layers promotes the fo rmation of a volatile oxide (SiO), and generates void nucleation sites . (C) 1997 American Institute of Physics.