Photoluminescence from SiO2 nanostructures prepared by a sequential RIE process

SiO₂ nanostructures have been fabricated by sequential etching/passivation treatment of an amorphous SiO₂ layer, using mixture of SF₆, H₂ and O₂ gases. Photoluminescence measurements depicts that nano-textured SiO₂ films have emission spectra between 530 and 580 nm depending on the details of the sample treatment. The effects of sequence numbers, post-RIE-process hydrogenation treatment, and annealing temperature on the PL characteristics were explored. It is observed that annealing the porous SiO₂ nanostructures significantly increases the PL intensity. Increasing either the plasma current or hydrogenation time will cause a redshift in the PL spectrum. The morphology of the SiO₂ nanostructures has also been studied using field-emission scanning electron microscopy.