GROWTH AND ELECTRICAL-PROPERTIES OF ION-IMPLANTED FESI2 ON (111)SI

High dose implantation of Fe+ ions in (111)Si, followed by rapid thermal annealing at 1150-degrees-C for 10 s was used to grow continuous buried layers of metallic alpha-FeSi2. As verified by transmission electron microscopy, RBS and He ion channeling, these layers are buried with sharp interfaces but with a relatively poor crystal quality (chi(min) almost-equal-to 60%) and a large number of Fe vacancies (almost-equal-to 17%). Electrical measurements provided a specific resistivity of almost-equal-to 225 muOMEGA cm at room temperature. Beta-FeSi2 layers have been fabricated by transforming the alpha-FeSi2 layers to beta-FeSi2 layers by annealing in a furnace at temperatures below the phase transition temperature (almost-equal-to 950-degrees-C), specifically at 800-degrees-C for 17 h. The existence of nucleation seeds promotes this phase transformation. Therefore, we performed subsequent implantations of Fe+ ions in alpha-FeSi2 layers at room temperature prior to the second annealing.