Chemisorption of atomic oxygen on Si(100): Self-consistent cluster and slab model investigations

The dissociative chemisorption of oxygen on Si(100) is studied with use of an ab initio multiconfiguration self-consistent-field cluster approach and a self-consistent field pseudopotential slab simulation. The cluster calculations show, for the first time, that the dissociative adsorption of an oxygen molecule is exothermic by 3 eV thus providing strong support for atomic chemisorption. Furthermore, atomic oxygen in the first-layer bridging positions is found to be modestly more stable than in the on-top configuration; stable adsorption at both sites is possible. © 1984 The American Physical Society.