A new method for the detection of native oxide on Si with combined use of 16O(α,α)16O resonance and channeling

Native oxide on Si and very thin SiO2 films (less than 300 Å) formed on Si have been investigated with the combined use of 16O(α,α)16O 3.045 MeV resonant backscattering and channeling. Usually, oxygen surface peak in the channeling non-resonant Rutherford backscattering mode was used to estimate the SiO2 film thickness and Si atom distortions at the interface. But the method is insufficient to obtain information for native oxide on Si because of the low sensitivity to thin layers. We present a more sensitive method, a combination of 16O(α,α)16O resonant backscattering and channeling techniques. A clear oxygen signal for native oxide films was detected by this method. We have shown that the combined use of resonant backscattering and channeling is five times more sensitive when compared to a normal channeling method. Native oxide films with different fabrication conditions were investigated. Advantage and disadvantage of this method are also discussed.