Metastable molecular precursor for the dissociative adsorption of oxygen on Si(111)

The initial adsorption of oxygen on Si(111) surfaces proceeds via a molecular intermediate which is precursor to the stable dissociated adsorption state. This metastable precursor can only be observed under certain conditions; its conversion to the stable state depends on temperature, probe, surface structure, impurities, and oxygen coverage. The precursor is likely to be a peroxy-bridge configuration whereas the stable dissociated oxygen species forms short-bridge bonds between adjacent Si atoms.