Low Temperature Carbon Nanotube Fabrication using Very High Frequency-Plasma Enhanced Chemical Vapour Deposition Method

It is explained one of the carbon nanotube research progress in Indonesia. It is being attempted a carbon nanotube growth using the modifications of existing home made PECVD system, which are Very-High Frequency PECVD (VHF-PECVD) and Hot-Wire VHF-PECVD (HW-VHF-PECVD). They are catalytic growth processes, which various metal catalyst thin films were growth on the Silicon substrate, such as Fe catalyst grown by using dc-Unbalanced Magnetron Sputtering Method and Al as well as Ni catalyst grown by high vacuum thermal evaporation method. SiO2 buffer layer was also grown beneath the Al catalyst layer. Some post-treatments for the catalyst thin films were also conducted, which were post-annealing process under various atmosphere conditions, N2, NH3 and free air. By using a single gas source, which was methane as the source of carbon, a carbon nanotube fabrication has been attempted at relatively low temperature, 400°C. It was expected that the high value of plasma frequency could lead to higher dissociation rate of methane to produce much carbon radicals. Meanwhile, the usage of hot-wire filament was expected to pre-decompose some the methane gas before reach the reactor in order to produce some of hydrogen radicals, which might be needed for CNT growth process. From morphological characterization results, it has been achieved some carbon sub-microstructure, in 100 nm of grain size and vertically aligned. From the composition characterization results, it has been confirmed that carbon atoms fraction were quite significant and the catalytic growth mechanism was happened.