Effects of preoxidation on the reaction kinetics of oxygen molecules at Si(001) surface have been investigated by real-time ultraviolet photoelectron spectroscopy. A mode transition from decomposition to growth of surface oxides was found to exist at a certain initial oxide coverage, which is kinetically, not energetically, determined. By considering a change of balance between Si adatom and oxygen-monomer fluxes at the perimeter of oxide clusters, this mode transition is quantitatively described as a bifurcation of an autocatalytic-reaction rate equation.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)