Features of the Formation of the B_iB_s Defect in Si

The data on the features of the electronic absorption in boron-doped silicon irradiated at 80 K with 5 MeV electrons are presented in this paper. The electronic transition at a frequency of 4296.8 cm^–1 is revealed in the absorption spectra of as-irradiated boron-doped Si samples. The intensity of the registered line grows with the boron concentration. The formation of defect responsible for the 4296.8 cm^–1 line is independent of the presence of oxygen and carbon in the samples. The investigations show that the vacancies are not components of the defect related to the 4296.8 cm^–1 line. The study of the thermal stability of the revealed defect shows that the disappearance of line at the annealing is accompanied by the synchronous development of the 4385.2 cm^–1 absorption line associated with the B_iB_s defects. The revealed defect is identified as a precursor of a stable configuration of the B_iB_s complex.