Photoluminescence studies were made of B- or P-implanted thermal films. Two photoluminescence bands, at 4.3 and 2.6eV, were observed. In the case of the former, 2 photoluminescence excitation bands were observed at 5.0 and 7.4eV. On the basis of a close similarity of the photoluminescence and photoluminescence excitation bands to those observed in O-deficient bulk silica, the 4.3 and 2.6eV photoluminescence bands were attributed to O-deficient defects that were introduced by ion implantation. It was found that, whereas the 4.3eV band in bulk material decayed exponentially, the decay of the corresponding band in implanted thermal films obeyed a power law or stretched exponential relationship; thus suggesting a distribution of photoluminescence lifetimes. This implied that the O-deficient defects which were introduced by the ion implantation of thermal films were perturbed by the structural distribution of the surrounding Si-O-Si network; including the concentration of photoluminescence quenching centers.

H.Nishikawa, E.Watanabe, D.Ito, M.Takiyama, A.Ieki, Y.Ohki: Journal of Applied Physics, 1995, 78[2], 842-6