Electroluminescence from an Au-extra-thin silicon oxynitride film-Si structure

The electroluminescence (EL) at room temperature from Au-extra-thin silicon oxynitride (ETSON)-p-Si and Au-ETSON-n-Si structures is reported. The ETSON films (∼80 Å) were deposited by the rf magnetron sputtering technique, and Si₃N₄-Si composite targets were used (the area ratio of Si to Si₃N_t was ∼6%). The EL spectra were measured under forward bias ≥ 4 V after the ETSON films had been annealed at 300, 600, 800, and 1000°C in N₂ ambient for 30 min. The Au-ETSON-p-Si structure has a dominant EL band with peak wavelength around 680 nm, and its integrated EL efficiency is an order of magnitude higher than that from a Au-extra-thin Si-rich SiO₂ (ETSSO) film (∼80 Å)-p-Si structure. Distinguishing it from the Au-ETSSO-Si structure, which emits visible EL only when it is fabricated on p-Si, EL can also be observed in the Au-ETSON-n-Si structure under forward bias, and the two dominant EL bands peak one at around 700 nm and one at around 800 nm. Electron beam irradiation induces a new EL band peaked at 500 nm in the EL spectrum from an Au-ETSON-p-Si structure. From the experimental results it is suggested that electrons and holes from opposite sides tunnel into the ETSON layer and recombine radiatively at luminescence centres there.