Processing for optically active erbium in silicon by film co-deposition and ion-beam mixing

Techniques of film deposition by co-evaporation, ion-beam assisted mixing, oxygen ion implantation, and thermal annealingwere been combined in a novel way to study processing of erbium-in-silicon thinfilm materials for optoelectronics applications. Structures with erbium concentrations above atomic solubility in silicon and below that of silicide compoundswere prepared by vacuum co-evaporation from two elemental sources to deposit 200–270 nm films on crystalline silicon substrates. Ar ions were implanted at 300 keV. Oxygen was incorporated by O-ion implantation at 130 keV. Samples were annealed at 600 8C in vacuum. Concentration profiles of the constituent elements were obtained by Rutherford backscattering spectrometry. Results show that diffusion induced by ion-beam mixing and activated by thermal annealing depends on the deposited Si–Er profile and reaction with implanted oxygen. Room temperature photoluminescence spectra show Er transitions in a 1480–1550 nm band and integrated intensities that increase with the oxygen-to-erbium ratio. 2008 Elsevier B.V. All rights reserved.