Selective thermal desorption of ultrathin aluminum oxide layers induced byelectron beams

The mechanism of electron-beam-induced selective thermal desorption of ultr athin aluminum-oxide layer (similar to0.4 nm) on Si(001) surface was invest igated by using scanning reflection electron microscopy, reflection high-en ergy electron diffraction, and Auger electron spectroscopy. We found that t he change in the aluminum-oxide layer composition induced by electron-stimu lated oxygen desorption accounted for the selective thermal desorption of t he oxide layer. A systematic increase in the vacuum-annealing temperature t o 500 degreesC, 600 degreesC and 720 degreesC resulted in the formation of three-dimensional metal aluminum clusters, desorption of these clusters, an d creation of a nanometer-scale clean Si(001)-2x1 open window in the select ed electron-beam-irradiated area. (C) 2001 American Institute of Physics.