Electron field emission from thin films of amorphous carbon nitride synthesized by arc ion plating

Abstract

Field emission characteristics of amorphous carbon nitride (a-C:N) thin films were studied in the applied field strength range of up to 20 V/μm by comparing the characteristics of amorphous carbon (a-C) thin films. Both a-C:N and a-C films were deposited on Si substrates by means of shielded arc ion plating (SAIP) using nitrogen or argon as an operating gas, respectively, and graphite as a solid carbon source. The a-C:N films showed better field emission current densities than the a-C films. Nitrogen doping to a-C was found to be effective in order to improve the field emission characteristics. Among all of the fabricated a-C:N films, the film containing 23% nitrogen, prepared using a nitrogen arc plasma at a pressure of 1 Pa by applying a sample bias voltage of −100 V, showed the lowest threshold field and the highest emission current density. Furthermore, thickness of this a-C:N was optimized to be approximately 40 nm in order to obtain the best field emission characteristics, that is, a threshold field of 12 V/μm and an emission current density of 3.6 μA/cm 2 at a field of 20 V/μm.