Silanone(Si=O)on Si(100): intermediate for initial silicon oxidation

Infrared-absorption measurements and first-principles quantum chemical calculations reveal that the initial oxidation of clean $\mathrm{Si}\mathrm{}\left(100\right)-(2\mathrm{}\times 1)$ by ${\mathrm{O}}_2$ involves the formation of a metastable silanone intermediate, $\left(\mathrm{O}\right)\mathrm{Si}=\mathrm{O},$ containing two oxygen atoms presumably from the same ${\mathrm{O}}_2$ molecule. Oxygen insertion into the surface silicon Si-Si backbonds is either thermally activated (∼1-eV barrier) or induced by atomic hydrogen exposure with formation of novel dihydride intermediates.