PAREDES OLIVERA PATRICIA ALEJANDRA
Artículos
Título:
Oxidation of Hydrogenated Si(111) by a Radical Propagation Mechanism
Autor/es:
F. A. SORIA; E. M. PATRITO; P. PAREDES OLIVERA
Editorial:
AMER CHEMICAL SOC
Referencias:
Lugar: Washington; Año: 2012
Resumen:
he reactivity of the hydrogenated Si(111)
surface toward H2O and O2 was investigated in order to
elucidate the mechanism of oxidation of the first silicon bilayer
in air. Density functional theory calculations were performed to
identify elementary reaction steps and their corresponding
activation energy barriers. The perfect surface is unreactive
toward H2O and O2 at room temperature as deduced from the
high energy barriers found. However, isolated Si dangling
bonds, (Si3)Si·, surrounded by SiH groups, readily react with
O2 (but not with H2O), producing a silanone intermediate of
the form (Si2O)SiO· where one of the silicon back bonds is
oxidized. This intermediate is reached after a series of
elementary steps with very small activation energy barriers.
In the next step, the oxygen atom of the silanone group inserts into a Si−Si back bond, and the surface silicon dangling bond is
regenerated as a (SiO2)Si· moiety in which the silyl group has two oxidized back bonds