Recombination activity of iron-boron pairs in compensated p-type silicon

Recently, the possible presence of boron-phosphorus pairs in compensated Si has been proposed in order to explain the unexpected behaviour of boron-oxygen defects in this material. These B-P pairs should also lead to an altered recombination activity of Fe-acceptor pairs in compensated Si, since some of the Fe-acceptor pairs would also be bound to P atoms, altering their energy level and carrier capture properties. In this work, we have used carrier lifetime measurements on Fe-implanted compensated Si wafers, containing both B and P, to identify the Fe-acceptor complexes present. The results indicate that FeB pairs dominate these samples, implying that Fe-B-P complexes, and by extension, B-P pairs, are unlikely to be present in significant concentrations.