POSITRON-ANNIHILATION IN PROTON-IRRADIATED CZOCHRALSKI-GROWN SI

Defects introduced by 65 MeV proton irradiation into Czochralski-grown Si were investigated by the positron annihilation technique. Doppler broadening profiles of the annihilation radiation and lifetime spectra of positrons were measured as a function of isochronal annealing temp erature. Divacancies introduced by the irradiation were found to migra te above 200 degrees C and they formed stable vacancy-oxygen complexes such as V3On (n=1-3). These defects annealed out at similar to 500 de grees C. After the recovery of vacancy-oxygen complexes, oxygen cluste rs were found to be the predominant defect. The aggregation of the oxy gen clusters started above 800 degrees C.