A NEW METHOD FOR THE DETECTION OF NATIVE-OXIDE ON SI WITH COMBINED USE OF O-16(ALPHA,ALPHA)O-16 RESONANCE AND CHANNELING

Native oxide on Si and very thin SiO2 films (less than 300 Angstrom) f ormed on Si have been investigated with the combined use of O-16(alpha ,alpha)O-16 3.045 MeV resonant backscattering and channeling. Usually, oxygen surface peak in the channeling non-resonant Rutherford backsca ttering 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 O-16 (alpha,alpha)O-16 resonant backscattering and channeling techniques. A clear oxygen signal for native oxide films was detected by this metho d. We have shown that the combined use of resonant backscattering and channeling is five times more sensitive when compared to a normal chan neling method. Native oxide films with different fabrication condition s were investigated. Advantage and disadvantage of this method are als o discussed.