Ni-Si(111) interface: Growth of Ni2Si islands at room temperature

Ultrathin films (0–20 Å) of Ni have been deposited on atomically clean Si(111) surfaces at room temperature. The composition and morphology of the films have been determined, employing the high depth resolution obtainable in medium energy ion scattering. Disordered Ni2Si islands are formed, which grow laterally and in thickness with increasing Ni coverage. The silicide formation ends when the islands coalesce into a continuous film, at a Ni coverage of ≊8×1015 Ni atoms/cm2. During the silicide growth, the surfaces of the islands are rich in Si.