EPR Studies of Defects in Electron-Irradiated Silicon: A Triplet State of Vacancy-Oxygen Complexes.

摘要

Three new EPR spectra (Si-A14, -A15, and -A16) and two previously known spectra (Si-P2 and -P4) are observed for the first time in electron-irradiated silicon. The microscopic defect models are established as multivacancy-oxygen complexes with the oxygen(s) in Si-O-Si structure inside the vacancy chain: a (divacancy plus oxygen) for Si-A14, a (divacancy plus two oxygen) for Si-P2, a (trivacancy plus oxygen) for Si-P4, a (Trivacancy plus two oxygen) for Si-P5, and a (trivacancy plus three oxygen) for Si-A15. The number of vacancies in the chain is determined from the zero-field fine structure and the number of oxygens from the evolutionary kinetics, with the g tensor, 29Si hyperfine structure, and stress response providing strong supportive evidence. It is emphasized that some of these oxygen-dependent defects play an important role as trapping centers for other point defects. (Author)