Fabrication and characteristics of amorphous carbon films grown in pure methane plasma by using radio frequency plasma enhanced chemical vapor deposition

Amorphous carbon (a-C) films were fabricated in pure methane plasma by using the radio frequency plasma-enhanced chemical vapor deposition (RF PECVD) system. Surface morphology and roughness of the films were examined as a function of substrate temperature by atomic force microscopy (AFM). Field emission from the a-C films was examined as a function of substrate, temperature. We found that the roughness and the emission current of the films were improved considerably when the substrate temperature was higher than 600degreesC. From the results obtained by Raman spectroscopy, growth of graphite crystallites was promoted at high substrate temperature. Moreover, the surface morphology was abruptly changed at high substrate temperatures over 600degreesC. We discuss the field emission characteristics of the a-C films with. regard to the surface morphology and the structural features.