NUMERICAL MODELING OF THE POINT-DEFECT AGGREGATION DURING THE CZOCHRALSKI SILICON CRYSTAL-GROWTH

A real-time simulation using the numerical method was performed in order to study the aggregation process of the intrinsic point defects during the Czochralski crystal growth. It was found that the point defect aggregation is predominated by the recombination process between silicon interstitials and vacancies. In contrast, the contribution of the long-range diffusion of point defects is found to be negligible. In silicon saturated with interstitial oxygen the formation of vacancy-oxygen pairs leads to silicon interstitial saturation, which in turn gives rise to a formation of interstitial-type defects. Therefore, in addition to the crystal growth rate and the temperature gradient, the concentration of dissolved interstitial oxygen also plays a significant role in the aggregation process of point defects. In this work, a co-aggregation model of intrinsic point defects is proposed.