Continuous and planar single-crystal Ni${\mathrm{Si}}_2$ films (< 60 Å thick) have been grown on Si(100) and (111) by ultrahigh-vacuum techniques. Nickel deposition (< 20 Å) on atomically clean Si at room temperature, followed by low-temperature heating at ∼450°C, results in the growth of epitaxial Ni${\mathrm{Si}}_2$ films whose structure depends critically on the starting Ni thickness. The films are coherent, without misfit dislocations. The orientation of the (111) silicide can be controlled by the initial Ni thickness.

• Received 22 November 1982

DOI:https://doi.org/10.1103/PhysRevLett.50.429