High growth rate of vertically aligned carbon nanotubes using a plasma shield in microwave plasma-enhanced chemical vapor deposition

The vertically aligned carbon nanotubes were synthesized using microwave plasma-enhanced chemical vapor deposition. The high growth rate was achieved by avoiding the direct plasma irradiation on a substrate, in which the growth of carbon nanotubes occurs, using a plasma shield. Transmission electron microscopy and scanning electron microscopy were used to investigate the synthesis of carbon nanotubes without and with the plasma shield. It was found that the synthesis process of the carbon nanotubes with the shield possessed two growth stages, and the growth rate in the fast growth stage was 280 nm/s.