Infrared studies of vacancy-oxygen-related complexes in electron-irradiated Czochralski-silicon

The oxygen-related defects in CZ silicon during electron irradiation (1.5 MeV) and subsequent annealing in the range of 150-600 °C were investigated by means of FTIR. In the electron irradiation CZ-Si, vacancy-oxygen complex is one of the dominant defects and its concentration is proportional to electron dose but not related to oxygen concentration. In this work, it was focused on the identification of the weak band at 860 cm−1 which was originated from asymmetrical stretching vibrations of an oxygen atom in the negative VO complex. It exhibits the same thermal stability with neutral VO band at 830 cm−1. In addition, the intensity of 889 cm−1 band has never been observed to exceed that of the A-center, implying that only a partial transformation of VO into VO2 does occur.