Anomalous growth of carbon-coated nickel silicide nanowires

Carbon-coated nanowires were prepared on Ni catalyst loaded Si(100) wafer in an RF-CVD reactor. The nanowires grow straight with a length of more than 10 μm. The average diameter of the nanowires ranged in 20-40 nm. HRTEM, EDX, Raman, and XRD measurements demonstrated the nanowires were 30-40 nm diameter SiNi nanowires coated with a 1.5-1.7 nm carbon layer. The turn-on field of the C-coated NiSi nanowires was estimated to be ∼3.6 eV and a field-enhancing factor β of ∼1500. The catalytic growth mechanism of the SiNi nanowires was discussed on the basis of experimental results in this work.