Oxygen-carbon interactions in silicon: photoluminescence defect spectrum at 1.06 eV emission

We report a new luminescent defect with non-phonon emission at 1.0595 eV in silicon irradiated at high electron doses in the 1018 cm-2 range. Doping studies and 12C/13C and 16O/18O isotopic line shifts demonstrate that the defect forms upon oxygen-carbon interaction. Luminescence measurements at higher temperatures exhibit excited features consistent with an effective-mass like electron spectrum classifying the defect as a hole trap with hole binding energy of ≅79 meV. Stress data also hint to shallow bound electron and reveal low symmetry (triclinic) of the core defect. Similarities with the Ci-Oi 0.79 eV defect ('C line') are pointed out. (author) 22 refs., 6 figs., 1 tab