The decay kinetics of a photoluminescence signal which was observed at about 2.7eV were studied, in various samples of ion-implanted thermal oxide films, as a function of the implantation conditions. The photoluminescence which was observed in many samples had associated decay constants of less than the 10ms which was the commonly observed decay constant for silica glass. Changes in the decay constants and the photoluminescence intensity were found to be related to the mass and dose of the implanted ion. In spite of the short decay constant, the present 2.7eV photoluminescence was therefore still attributed to a triplet-to-singlet transition of O-deficient centers; as in the case of silica glass. The rapid decay was explained in terms of an increased spin-orbit coupling interaction that was due to structural deformation by ion implantation; such as the formation of paramagnetic defects and/or densification.

K.S.Seol, Y.Ohki, H.Nishikawa, M.Takiyama, Y.Hama: Journal of Applied Physics, 1996, 80[11], 6444-7