A new metastable complex in monocrystalline material which had been irradiated with protons at about 80K was studied. The electron paramagnetic resonance spectra of Si-AA13 (C3v symmetry) and Si-AA14 (C1 symmetry), as well as the known Si-A18 spectrum, originated from differing molecular configurations of the complex. Complete conversion between the metastable configurations was achieved by annealing at about 190K (A18 to AA13) and by prolonged illumination with band-gap light at 77K (AA13 to AA14 to A18). The deep electron levels of the complex were established. A preferential stress-induced alignment of interstitial O at 450C, in as-grown samples, as well as AA13 defect alignment at 1200K (after irradiation), indicated that interstitial O was involved in the structure of the center. It was tentatively suggested that the defect was a self-interstitial plus O-interstitial complex. A new self-interstitial related center (AA12) was also observed after annealing out the O-related metastable complex.

K.A.Abdullin, B.N.Mukashev, J.V.Gorelkinskii: Semiconductor Science and Technology, 1996, 11[11], 1696-703