Surface oxidation of Si assisted by irradiation with large gas cluster ion beam in an oxygen atmosphere

Surface oxidation of Si assisted by Ar cluster impact with a current density of a few μA/cm2 under O2 atmosphere was investigated. Thin-film formation by cluster ion beam presents a number of advantages such as atomic-scale surface smoothing, high density and precise stoichiometry. We used an Ar cluster ion beam with 20 keV and a mean size of 1000 atoms per cluster and measured the emission yields of Si+ and SiO+ after Ar cluster ion irradiation in O2 atmosphere using a quadrupole mass spectrometer to investigate the dependence of Si surface oxidation on oxygen partial pressure. It was found that the Si surface was oxidized by Ar cluster ion irradiation in O2 atmosphere.