Growth process conditions of vertically aligned carbon nanotubes using plasma enhanced chemical vapor deposition

The growth of vertically aligned carbon nanotubes using a direct current pl asma enhanced chemical vapor deposition system is reported. The growth prop erties are studied as a function of the Ni catalyst layer thickness, bias v oltage, deposition temperature, C2H2:NH3 ratio, and pressure. It was found that the diameter, growth rate, and areal density of the nanotubes are cont rolled by the initial thickness of the catalyst layer. The alignment of the nanotubes depends on the electric field. Our results indicate that the gro wth occurs by diffusion of carbon through the Ni catalyst particle, which r ides on the top of the growing tube. (C) 2001 American Institute of Physics .