Photoluminescence of erbium in SiOxNy alloys annealed at high temperature

Amorphous silicon oxynitride SiOxNy ternary alloys were prepared by reactive evaporation, with stoichiometries varying between Si0.47O0.05N0.48 and Si0.35O0.65. These thin films were doped with erbium during the evaporation process with an effusion cell. The composition and the atomic structure were determined by X-ray photoelectron spectroscopy (XPS), infrared (IR) absorption spectrometry, and Raman spectrometry. Photoluminescence (PL) experiments were carried out in the visible and infrared ranges. The Er signal was maximum for equal amounts of oxygen and nitrogen in the SiOxNy alloys. It disappears for oxygen contents greater than 30%. Photoluminescence excitation (PLE) experiments show that the PL is due to an indirect excitation process from the pure silicon domains.