Formation of ultra-thin oxide film at silicon(001) by well-characterized hyperthermal broad oxygen atom beam exposed at room temperature

Tagawa, Masahito*; Yokota, Kumiko*; Yoshigoe, Akitaka ; Teraoka, Yuden

H-terminated Si(001) surfaces were exposed to O-atom beams formed by laser-detonation techniques. Effects of sample temperature, flux and energy of the O-atom on the Si oxidation were investigated. The suboxides content was also studied by synchrotron radiation photoelectron spectroscopy. It was confirmed that the oxide growth was achieved even at room temperature and the oxide thickness reached a few nanometers depending upon the oxidation conditions. It was also suggested that the amount of suboxides is quite low. The oxidation process was divided into two stages: the fast oxidation stage and the subsequent slow oxidation stage. It was also confirmed that the reaction yield of O-atom increased with increasing its translational energy. The characteristics of the O-atom beam oxidation was explained by the effect of energy accommodation from the incident O-atoms to the surface Si atoms.