Electronic absorption of interstitial boron-related defects in silicon

摘要

We report the data on the electronic absorption of interstitial boron-related defects in silicon, irradiated with 5MeV electrons. Two new electronic absorption features have been revealed in the spectrum of boron-doped Si. The sharp line at 4385.2cm~(-1) is detected in Si irradiated at 80 K and subjected to the subsequent annealing up to 300 K. The emergence of the registered line depends on the concentration of boron and docs not depend on the presence of oxygen and carbon in the samples. The revealed line is associated with B_iB_s complex. It is shown that the presence of oxygen in the samples inhibits the formation of B_iB_s defects. The disappearance of the 4385.2 cm~(-1) line upon annealing is accompanied by the emergence of a line at 7829.5 cm~(-1) in the spectrum. The appearance of the 7829.5 cm~(-1) line depends on the presence of carbon in the samples. The registered 7829.5 cm~(-1) line is ascribed to B_iC_s complex. It is argued that, in the oxygen-rich material, B; liberated as a result of the dissociation of both B_iO_i and B_iB_s defects are involved in the formation of B_iC_s In oxygen-lean Si. only B_i liberated at the dissociation of B_iB_s participate in the formation of B_iC_s.