We demonstrate the growth of self-assembled nanowires of cobalt silicide on Si(111), (100), and (110) substrates during deposition of Co onto a heated Si substrate. Silicide islands form via an endotaxial mechanism, growing into the substrate along inclined Si{111} planes, which breaks the symmetry of the surface and leads to a long, thin nanowire shape. During growth, both the length and width of the islands increase with time in a fixed proportion that varies strongly with growth temperature, which shows that the nanowire shape is kinetically determined. It is expected that nanowires could form in many other overlayer/substrate systems via this mechanism.

Dysprosium deposited on Si(110) at 720 °C is observed to form self-assembled silicide nanowire (NW) structures with a single orientation and average dimensions of 15 nm wide and microns long. The NW sides grow into the substrate along inclined Si{111} planes, forming a V-shaped cross section with an interface that is coherent on one side, described by DySi2(0001)//Si(111_) and DySi2[011_0]//Si[1_10], and incoherent on the other. This type of growth represents a physical mechanism for self-assembled NW formation that does not require anisotropic lattice mismatch.

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We have measured the electrical properties of self-assembled epitaxial NiSi2 nanowires (NWs) formed on Si substrates. We find quantum corrections due to weak antilocalization and electron–electron interactions. Analysis of the magnetoresistance indicates that electron phase coherence in the NWs is limited by Nyquist dephasing below 10K, and by electron–phonon scattering at higher temperatures. The phase-breaking and spin–orbit scattering lengths are found to be ∼45nm and 3–7nm, at 4.2K, respectively, similar to reports for thin NiSi2 films.

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