Stress-driven oxidation chemistry of wet silicon surfaces
Lucio Colombi Ciacchi,1,2
Daniel J. Cole,3
Mike C. Payne,3
Peter Gumbsch1,2
1Fraunhofer Institut für Werkstoffmechanik, 79108 Freiburg, Germany
2Institut für Zuverlässigkeit von Bauteilen und Systemen,
University of Karlsruhe, 76131 Karlsruhe, Germany
3Theory of Condensed Matter Group, Cavendish Laboratory,
University of Cambridge, CB3 0HE, UK
The formation of a hydroxylated native oxide layer on Si(001) under wet
conditions is studied by means of first principles molecular dynamics
simulations.
Water molecules are found to adsorb and dissociate on the oxidised surface
leading to rupture of Si-O bonds and producing reactive sites for attack
by dissolved dioxygen or hydrogen peroxide molecules.
Tensile strain is found to enhance the driving force for the dissociative
adsorption of water, suggesting that similar reactions could be
responsible for environmentally-driven sub-critical crack propagation
in silicon.
Journal of Physical Chemistry C 112, 12077 (2008)
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