Optical absorption lines due to H-2-related defects in Si

Optical absorption spectra of hydrogen (H)-doped Si crystals were studied t o clarify the hydrogen-related optical absorption peaks. Hydrogen was doped in Si crystals by annealing them in a hydrogen atmosphere at 1200 degrees C followed by quenching. Some specimens were irradiated with high energy el ectrons (3 MeV) or neutrons. Some specimens were treated with atomic hydrog en. Their optical absorption spectra were measured at about 7 K with an FT- IR spectrometer. In accordance with Pritchard et al. an absorption peak was observed at 3618 cm(-1) in H-doped specimens. Its intensity became weaker after electron or neutron irradiation. Instead, many absorption peaks appea red around 2000 cm(-1) and an absorption peak appeared at 3942 cm(-1). The responsible defect for the latter peak does not include H. Many absorption peaks around 2000 cm(-1) were compared with those observed in proton-implan ted Si.