Characteristics of carbon and carbon-nitride nanostructures produced by plasma deposition from ammonia and methane or acetylene

Carbon/carbon-nitride nanostructures were deposited by rf plasma enhanced and thermal chemical vapour deposition (PECVD and CVD). The growth of nanostructures was studied under several deposition conditions of negative self-bias (below -600V), C2H2:NH3 and CH4:NH3 ratios (varying from 0.5 to 1.0), substrate (Si and Cu) and substrate temperature (from 650 degrees C to 800 degrees C). It was found that the use of C2H2 or CH4 as the carbon source gave rise, respectively, to carbon nanotubes and carbon-nitride nanorods under similar deposition conditions. The resulting films were characterized by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), electron energy loss spectroscopy (EELS) and Raman spectroscopy. The results have been discussed in terms of growth deposition conditions.