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Adsorption of H2O on planar and stepped Si(100): Structural aspects

Larsson, Christer LU ; Johnson, Allen; Flodström, Anders and Madey, Theodore (1987) In Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films 5(4). p.842-846
Abstract
The adsorption of water on two silicon surfaces [reconstructed planar (100)2×1 and single domain stepped (100)2×1 cut 5° towards (011)] was studied using low-energy electron diffraction and digital imaging electron stimulated desorption ion angular distributions (ESDIAD) as a function of temperature (145–700 K) and coverage. Water has been shown previously to chemisorb dissociatively to form surface OH groups. At 300 K the H + ESDIAD pattern for the planar surface is a nearly symmetric halo, indicating that OH is oriented with its bond vector inclined away from the surface normal, while at low temperatures (200 K) a four-lobed pattern that preserves substrate symmetry is observed. This reversible temperature dependence is related to... (More)
The adsorption of water on two silicon surfaces [reconstructed planar (100)2×1 and single domain stepped (100)2×1 cut 5° towards (011)] was studied using low-energy electron diffraction and digital imaging electron stimulated desorption ion angular distributions (ESDIAD) as a function of temperature (145–700 K) and coverage. Water has been shown previously to chemisorb dissociatively to form surface OH groups. At 300 K the H + ESDIAD pattern for the planar surface is a nearly symmetric halo, indicating that OH is oriented with its bond vector inclined away from the surface normal, while at low temperatures (200 K) a four-lobed pattern that preserves substrate symmetry is observed. This reversible temperature dependence is related to librations and rotations of the OH complexes. ESDIAD from the stepped surface exhibits a two-lobed pattern, with enhanced emission towards the steps, consistent with bonding of OH to single-domain terrace sites. An interpretation is presented based on the dimer model of the Si(100) reconstruction in which the OH bond axis azimuths are oriented nearly perpendicular to the dimer azimuths. (Less)
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keywords
SURFACE RECONSTRUCTION, ADSORPTION, DESORPTION, CRYSTAL STRUCTURE, SILICON, WATER, HYDROXYL RADICALS, SORPTIVE PROPERTIES, ELECTRON STIMULATED DESORPTION, SURFACE STRUCTURE, SURFACE PROPERTIES
in
Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films
volume
5
issue
4
pages
842 - 846
publisher
American Vacuum Society
external identifiers
  • scopus:0001508476
ISSN
1520-8559
DOI
10.1116/1.574322
language
English
LU publication?
no
id
8036eae6-1912-4fdd-bbcc-53dbce045bea (old id 1056648)
date added to LUP
2008-04-16 15:28:41
date last changed
2017-07-30 03:50:13
@article{8036eae6-1912-4fdd-bbcc-53dbce045bea,
  abstract     = {The adsorption of water on two silicon surfaces [reconstructed planar (100)2×1 and single domain stepped (100)2×1 cut 5° towards (011)] was studied using low-energy electron diffraction and digital imaging electron stimulated desorption ion angular distributions (ESDIAD) as a function of temperature (145–700 K) and coverage. Water has been shown previously to chemisorb dissociatively to form surface OH groups. At 300 K the H + ESDIAD pattern for the planar surface is a nearly symmetric halo, indicating that OH is oriented with its bond vector inclined away from the surface normal, while at low temperatures (200 K) a four-lobed pattern that preserves substrate symmetry is observed. This reversible temperature dependence is related to librations and rotations of the OH complexes. ESDIAD from the stepped surface exhibits a two-lobed pattern, with enhanced emission towards the steps, consistent with bonding of OH to single-domain terrace sites. An interpretation is presented based on the dimer model of the Si(100) reconstruction in which the OH bond axis azimuths are oriented nearly perpendicular to the dimer azimuths.},
  author       = {Larsson, Christer and Johnson, Allen and Flodström, Anders and Madey, Theodore},
  issn         = {1520-8559},
  keyword      = {SURFACE RECONSTRUCTION,ADSORPTION,DESORPTION,CRYSTAL STRUCTURE,SILICON,WATER,HYDROXYL RADICALS,SORPTIVE PROPERTIES,ELECTRON STIMULATED DESORPTION,SURFACE STRUCTURE,SURFACE PROPERTIES},
  language     = {eng},
  number       = {4},
  pages        = {842--846},
  publisher    = {American Vacuum Society},
  series       = {Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films},
  title        = {Adsorption of H2O on planar and stepped Si(100): Structural aspects},
  url          = {http://dx.doi.org/10.1116/1.574322},
  volume       = {5},
  year         = {1987},
}