Oxygen containing silicon clusters on Teflon and their work functions studied with X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy

Silicon species were deposited on tetrafluoroethylene (Teflon) with pulsed laser silicon ablation at 532 nm under UHV. Surface species were studied with X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). Tetrafluorocarbon (CF4) was easily desorbed by the decomposition reaction of Teflon with flying silicon species. Surface species were characterized as a function of pulsed laser shots. Silicon species were terminated with oxygen in gas phase to form two kinds of SiOx clusters (x < 0.3) in addition to oxygen terminated silicon networks. Their work functions could be estimated by the shift of their Fermi energies. (C) 1999 Elsevier Science B.V. All rights reserved.