Influence of carbon and preannealing on the formation of oxygen-induced recombination centres in heat-treated silicon

Abstract

The effect of carbon on the formation of oxygen-induced recombination centres at 450 and 650 °C and of 450 °C preannealing on the formation of oxygen-induced recombination centres at 650 °C is studied in silicon crystals of varying oxygen content. It is found: a) a moderate amount of carbon atoms promotes the formation of oxygen-related recombination centres at 650 °C; b) a high amount of carbon atoms suppresses the formation of oxygen-related recombination centres at 450 and 650 °C; c) prolonged 450 °C preannealing of silicon promotes the formation of oxygen-induced recombination centres at 650 °C (the effect of preannealing is stronger for crystals with a moderate amount of carbon atoms). The results found are explained in terms of generation (by carbon) and preannealing of nucleation sites for oxygen-related recombination centres (this leads to a carbon-and preannealing-induced increase in the concentration of the oxygen-induced recombination centres) and of an effective trapping of oxygen atoms by carbon atoms resulting in a marked reduction of the available oxygen content (this leads to a carbon-induced decrease in the concentration of oxygen-related recombination centres). [Russian Text Ignored].