Theoretical study on adsorption state of chemisorbed oxygen molecule on partially oxidized Si(001) surface

Abstract

We theoretically investigate the structures and electronic states of a chemisorbed oxygen molecule on partially oxidized Si(001) surfaces by using first-principles calculation. For two configurations, paul and grif, suggested as a chemisorbed oxygen molecule, we obtained: (i) the grif is more stable than the paul, while the relative stability between the two depends on the surrounding structures. (ii) The charge states of the paul and the grif are −1 and −2, respectively. (iii) The paul is spin polarized, while the grif is not. (iv) The paul exhibits two peaks in the XPS calculation, while the grif exhibits one degenerate peak. These results provide fundamental information for the surface species to understand the oxidation process of Si(001) surfaces.