Visible luminescence induced by Si-ion implantation into Si single crystals covered with a thin SiO2 layer

An investigation of Si ion implantation into Si single crystals covered with a SiO2 layer of various thicknesses (1000-3000 Angstrom) was conducted and new characteristic luminescence bands were observed. A visible band that peaked around 1.89 or 2.0 eV was observed from the as-implanted samples. after high temperature post annealing, a visible band located in the range of 1.7 eV was detected. Interestingly, a new luminescence band around 1.5 eV was observed, for the first time, in a sample covered with a 3000 Angstrom SiO2 layer, after high dose implantation and annealing. We report, in this letter, the experimental results and a brief discussion concerning the various possible mechanisms responsible for the observed luminescence bands.