Charge state of luminescence centers in the Si-SiO2 structures subjected to sequential implantation with silicon and carbon ions

Electroluminescence of Si-SiO₂ structures subjected to sequential implantation of silicon and carbon ions and to postimplantation annealing is studied. It is shown that two bands appear in the electroluminescence spectrum with energies of 2.7 and 4.3 eV as a result of ion implantation. After annealing, the band peaked at the energy of 3.2 eV appears in the spectrum; this band can be related to the formation silicon-carbide clusters. Charge characteristics of the structures under study are obtained. It is shown that the luminescence centers responsible for all bands are not charged.