In-situ characterization of iron silicide islands on Si(111)

Abstract

Iron silicide islands grown on Si(111) substrates by either solid-phase epitaxy (SPE) or reactive deposition epitaxy (RDE) were examined with an ultrahigh-vacuum transmission electron microscopy-scanning tunnelling microscopy integrated characterization system. Several types of islands (small triangles, parallelograms, middle-sized rectangles and larger random roundish islands) were obtained, depending on the Fe deposition thickness and substrate temperature. The roundish islands showed moiré fringes in one direction and are identified as β-FeSi2; they had more strain than the other types of islands. The triangular, rhomboid and rectangular islands showed a 2 × 2 surface phase and possessed a roughly cubic structure. More of the well-shaped islands were found on the specimens obtained by RDE.