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 wi th X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spe ctroscopy (UPS). Tetrafluorocarbon (CF4) was easily desorbed by the decompo sition reaction of Teflon with flying silicon species. Surface species were characterized as a function of pulsed laser shots. Silicon species were te rminated 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.