INFLUENCE OF CARBON AND PREANNEALING ON THE FORMATION OF OXYGEN-INDUCED RECOMBINATION CENTERS IN HEAT-TREATED SILICON

The effect of carbon on the formation of oxygen-induced recombination centres at 450 and 650 degree C and of 450 degree C preannealing on the formation of oxygen-induced recombination centres at 650 degree C is studied in silicon crystals of varying oxygen content. It is found: a moderate amount of carbon atoms promotes the formation of oxygen-related recombination centres at 650 degree C; a high amount of carbon atoms suppresses the formation of oxygen-related recombination centres at 450 and 650 degree C; prolonged 450 degree C preannealing of silicon promotes the formation of oxygen-induced recombination centres at 650 degree 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.