SiO Mass Spectrometry and Si-2p Photoemission Spectroscopy for the Study of Oxidation Reaction Dynamics of Si(001) Surface by Supersonic O2 Molecular Beams under 1000 K

Abstract

The Si18O desorption yield was measured in the Si(001) surface temperature region from 900 K to 1300 K at the 18O2 incident energies of 0.7 eV, 2.2 eV and 3.3 eV. The Si18O desorption yield in a surface temperature region higher than 1000 K increased with increasing incident energy, indicating the incident-energy-induced oxidation and the variation of angular distribution of Si18O desorption. Inversely, the Si18O desorption yield decreased with increasing incident energy in the region from 900 K to 1000 K, indicating the coexistence of the passive and the active oxidation. In order to clarify the reaction mechanisms of the later phenomenon, real-time in-situ Si-2p photoemission spectroscopy has been performed. The obtained Si-2p spectra showed the variation of the oxide-nuclei quality from the sub-oxide-rich structure to the SiO2-rich structure. The formation of the SiO2 structure suppresses the SiO desorption due to the enhanced O2 sticking at backbonds by the action of incident energy.