Reduction of iron diffusion in silicon during the epitaxial growth of β-FeSi2 films by use of thin template buffer layers

High-quality β-FeSi2 films were fabricated by the facing-target sputtering (FTS) method. It was found that an epitaxial thin β-FeSi2 template buffer layer performed on Si substrate was essential for the epitaxial growth of thick β-FeSi2 film. The mechanism for reducing Fe diffusion into Si was also discussed with respect to the dependence of the β-FeSi2 epitaxial growth temperature on the thickness, the stability of the compound and features of Fe diffusion in Si. The results indicate that a template layer for the growth of thick β-FeSi2 layers is useful for obtaining β-FeSi 2/Si heterojunctions for photosensor and thin film solar cell applications.