Noble gas ion effects on the XPS valence band spectra of silicon

X-ray photoelectron spectroscopy (XPS) has been used to study crystalline silicon (c-Si) (1 0 0) surfaces bombarded with argon, xenon and neon to examine the interaction of core peaks from these noble gases with the valence band region of silicon. XPS valence band spectra of xenon- and argon-bombarded silicon were found to have prominent peaks at binding energies of approximately 6 eV for the xenon (5p(1/2), 5P(3/2)) and 9.3 eV for the argon (3p) core levels, respectively. These core level peaks are within the silicon valence band energy range. Attempts to compensate for the interfering peaks are reported but it is concluded that it is better to select a bombarding ion whose core levels do not overlap with the silicon valence band. Results for the ion bombardment are reported for neon, which has a peak at approximately 15.5 eV that does not significantly interfere with the photoelectron valence band spectrum of silicon. (C) 2003 Elsevier B.V. All rights reserved.