Development of a Laser-Assisted Chemical Vapor Deposition System for the Growth of Carbon Nanotubes

We developed the chemical vapor deposition (CVD) system in which the pulsed UV laser (a fourth-harmonic Nd:YAG laser, = 266 nm, pulse width = 4.3 ns, repetition frequency = 10 Hz) can be introduced. This CVD system is based on the cold-wall thermal CVD. The substrate, on which the growth catalysts are deposited, can be heated by resistance heating and be irradiated with UV laser. We used a commonly-used Fe/Co supported on zeolite catalyst for carbon nanotube growth. The catalyst was coated on a 10 mm 10 mm Si substrate. Ethanol gas was used as a carbon source. In the CVD process, the substrate is heated by resistance heating at 300 o C, then ethanol gas is supplied in the CVD chamber with the pressure around 1000 Pa, after that the laser is irradiated to the substrate. We have examined the dependence of the laser fluence on the grown carbon nanotubes (CNTs). The growth area and growth amount of CNTs depend on the laser fluence. CNTs were synthesized at the laser spot with the laser fluence of 0.05 J/cm 2 .