Effect of point defects on oxygen aggregation in Si at 450 °C

The oxygen aggregation process at 450 °C has been investigated by comparing the distributions of the interstitial oxygen, the thermal donor (TD), and the defect responsible for the photoluminescence (PL) line at 0.767 eV in a rapidly cooled Czochralski-grown Si crystal in which point defects are frozen-in nonuniformly in the growth direction. The formations of the TD and the 0.767-eV PL defect are delayed in the vacancy-rich region, which is not explained by the oxygen variation. The present result leads us to suggest that the oxygen aggregation is retarded by excess vacancies, which is consistent with the reported models for the oxygen aggregation at 450 °C.