Synthesis of iron silicides starting with Fe / Si multilayers

The iron silicides are considered key materials for silicon integrated optoelectronic devices. This report describes the synthesis ofthe iron silicides starting with e-beam evaporated multilayered Fe/Si samples. Samples with two chemical wavelengths were studied upon annealing and ion beam ixing. The characterization included X-ray diffraction, CEMS a d Rutherford backscattering. The FeSi2 silicide is a very interesting material for silicon technology. The beta phase of this silicide is a semiconductor with a direct band gap of around 0.87 eV which makes it an ideal coupler for optoelectronic devices directly integrated on silicon to optical fibers [1]. Besides this semiconducting phase exists the metallic a-FeSi2, and both phases can be grown with lattice constants close to the one of sili-con and an epitaxial formation can be achieved. These important aspects created a recent rush towards the production and characterization f this material. While in bulk samples the iron silicides are formed at high temperatures, several works of thin film deposition [2-4], RTA [5], pulsed laser irradiation [6] and ion beam techniques [7-9] have been reported about he process of formation at lowe