Theoretical Investigation of the Reaction Pathway of O Atom on Si(001)-(2 x 1)

Structural, energetic, and mechanistic features of the initial steps of the reaction of an O atom with Si(001)-(2 x 1) were modeled by the use of a Si(9)H(12) + O system. Transition state structures (TSs) and equilibrium structures (EQs) as well as dissociation channels (DCs) were systematically searched using a global reaction route mapping (GRRM) technique on the potential energy surface (PES) based on the scaled hypersphere search (SHS) algorithm. The first six low-energy structures were consistent with known structure models for oxygen adsorption on the dimer of Si(001)-(2 x 1). Other structures with higher energies could be well interpreted as intermediates leading toward reaction paths for migration/dissociation occurring at high temperatures.