Carbon films with high density nanotubes produced using microwave plasma assisted CVD Original Research Article

The preparation of massive carbon nanotubes on silicon, quartz and ceramic substrates using microwave plasma enhanced CVD is reported. The nanotubes, ranging from 10 to 120 nm in diameter and a few tens of microns in length, were formed under hydrocarbon plasma at 720°C with the aid of iron-oxide particles. It is found that the morphology of the nanotubes is strongly influenced by the flow ratio of methane to hydrogen. Defect-less nanotubes with small diameters are favourably produced under a small flow ratio. In contrast, defect-rich nanotubes with large diameters and highly disordered growth directions are formed at a large flow ratio.