Present Status and Issues of Carbon Nanotubes Alighned Growth Using Plasma Process 6. Effect of Negative Direct-Current Bias on Aligned Growth of Carbon Nanotubes

Abstract

The effect of negative direct-current bias on vertically aligned growth of carbon nanotubes by plasma-enhanced chemical vapor deposition is investigated. The experimental results showed that negative direct-current bias to a substrate enhanced the aligned growth of carbon nanotubes, due to the electrostatic attraction of the negatively charged tips of the carbon nanotubes toward the plasma in the strong sheath electric field. It was also shown that the accelerated positive ions in the strong sheath electric field affected the suppression of growth of catalytic metal particles by sputtering, thereby contributing to the formation of carbon nanotubes.