Fabrication and Characteristics of Amorphous Carbon Films Grown in Pure Methane Plasma by using Radio Frequency Plasma Enhanced Chemical Vapor Deposition

Abstract

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 600°C. 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 600°C. We discuss the field emission characteristics of the a-C films with regard to the surface morphology and the structural features.