The effect of nickel contamination under rapid thermal processing （RTP） on the magic denuded zone （MDZ） in Czochralski silicon is investigated. It is found that the bulk defects can effectively getter nickel atoms once the MDZ forms. However,if the silicon sample is initially contaminated with nickel, the MDZ cannot form during the subsequent RTP,and a high density of precipitates occurs near the surface. In conventional IG processes,the DZ can form regardless of the nickel contamination sequence. Based on the facts,we propose that the formation of nickel silicide （Ni3Si） at the surface keeps the concentration of vacancies in the near-surface zone still higher than the critical concentration for oxygen precipitation under the subsequent RTP, which prevents MDZ formation.
The effects of the transition metals copper and nickel on oxygen precipitation in Czochralski silicon under a rapid thermal process are investigated. It is found that interstitial copper has almost no effect on oxygen precipitation,but copper precipitation markedly enhances oxygen precipitation. However, neither interstitial nickel nor nickel precipitation affects oxygen precipitation. The reasons for the effects of copper and nickel contamination on oxygen precipitation are discussed in light of oxygen precipitation nucleation theory.
