Complexes of point defects and impurities in electron-irradiated CZ-Si doped with hydrogen

Abstract

We studied complexes generated by electron-irradiation of CZ-Si crystals pre-doped with hydrogen (H) from the measurements of optical absorption spectra. Specimens were prepared from a non-doped CZ-Si crystal. They were doped with H by heating at 1300°C in H 2 gas. They were then irradiated with 3-MeV electrons at room temperature. We measured their optical absorption spectra by an FT-IR spectrometer at about 7 K. An 836-cm −1 peak which is due to a V–O pair was very strong. Optical absorption peaks due to complexes of H and self-interstitial (I) such as IH 2 (1987-cm −1 peak), I 2H 2 (1870-cm −1 peak) and I 3H 2 (1959-cm −1 peak) were stronger than those of FZ-Si. Due to isochronal annealing, the intensity of V–O pair decreases at above 100°C. Simutaneously with this decrease, two new peaks appeared at about 2126 and 2151 cm −1. This is due to a formation of VOH 2 complex by a reaction between a V–O pair and a H 2.