Direct insertion of oxygen atoms into the backbonds of subsurface Si atoms using translational energies of oxygen atom beams

Tagawa, Masahito*; Yokota, Kumiko*; Tsumamoto, Shinnosuke*; Sogo, Chie*; Yoshigoe, Akitaka ; Teraoka, Yuden

A direct oxidation reaction of Si atoms on an Si(001) surface was studied by ellipsometry and synchrotron radiation photoemission spectroscopy. In-situ ellipsometry measurements when exposed to 2.7-5.0 eV O atom beams indicated that oxide growth followed a linear relationship with an O atom fluence up to an oxide thickness of 0.6-0.7 nm. In contrast, the limit of linear growth was 0.3 nm in the case of the 1.8 eV beam. These results suggest that the backbonds of Si atoms in the first layer are directly oxidized by O atom with a translational energy between 2.7-5.0 eV.