Luminescence from Si/SiO₂ with Si Implantation

Silicon single crystals with a SiO₂ overlayer of various thicknesses ( 1000-6000Å ) were implanted by 120 and 160keV Si-ions to doses in a range of (0.5-1.0)x10¹⁷cm^-2 to study the visible light emission in their as-implanted and post-annealed states. An emission band peaked around 2.0eV was visible in the photoluminescence (PL) spectra of all the as-implanted samples. After post-annealing at 1100°C in a flowing N₂ gas, it was found that a visible band peaked in the range of 1.7eV is detectable from all the samples and that the PL intensity exihibits a correlation with the oxygen concentration in the implanted region. Possible mechanisms responsible for the observed light emission were also discussed.