Direct Diameter-Controlled Growth of Multiwall Carbon Nanotubes on Nickel-Silicide Layer

By using plasma-enhanced chemical vapor deposition (p-CVD), we grew vertically aligned multiwall carbon nanotubes (CNTs) directly on a nickel-silicide layer, which can be used as electrodes for metal-oxide-semiconductor field-effect transistors (MOSFETs). By using a nickel-silicide layer as a catalyst, the nanotube diameter became smaller than that possible with a nickel film catalyst. We suggest that Ni-silicide composition plays an important role in controlling the diameter of the nanotubes. To our knowledge, this is the first report on diameter-controlled vertically aligned CNT growth on catalytic metal-silicide substrates.