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 temperature. Divacancies introduced by the irradiation were found to migrate above 200° C and they formed stable vacancy-oxygen complexes such as V3On (n=1–3). These defects annealed out at ~500° C. After the recovery of vacancy-oxygen complexes, oxygen clusters were found to be the predominant defect. The aggregation of the oxygen clusters started above 800° C.