Fabrication of spherical carbon via UHF inductively coupled microplasma CVD

We developed a CVD system employing inductively coupled micronplasma generated by applying UHF (UHF microplasma). This system can be operated easily in air at atmospheric pressure with a few tens of watts of UHF power and enables us to deposit material on a wide variety of substrates. Deposition of carbon from CH4/Ar gas on the substrate without additional heating at atmospheric pressure in ambient air resulted in the formation of spherical graphites on a micron-sized region, at a growth rate of about 2 µm min−1. In addition, carbon nano-onions of sub-30-nm diameters were formed in large quantity. Our results seem to suggest that this microplasma CVD system may be utilized in the near future for low-temperature preparation of crystallized nanostructures, leading to simplified fabrication of the nano-scale device.