Orientation dependence of the initial oxidation of H-terminated Si surfaces studied by high-resolution electron energy loss spectroscopy

The initial oxidation of D-terminated Si(100) and Si(311) surfaces has been investigated using high-resolution electron energy loss spectroscopy. The initial sticking probability of oxygen atoms on a D-terminated Si(311) surface is about twice as large as that on a D-terminated Si(100) surface. This result can be explained by the differences in the adsorption sites of oxygen atoms, Moreover, the oxygen atoms adsorb on the adsorption sites at random in the initial stages of oxidation on the D-terminated Si(311) surface, in contrast with the case of the D-terminated Si(100) surface. The local bonding structures of Si-O-Si formed on the D-terminated Si surfaces depend on the surface orientation, while the structures on Si clean surfaces are scarcely influenced.