Amorphous Hydrogenated Carbon-Nitrogen Films Deposited by Plasma-Enhanced Chemical Vapor Deposition

Abstract

Recent results on the composition, structural characterization and mechanical properties of amorphous hydrogenated carbon-nitrogen films (a-C(N):H) deposited by plasma enhanced chemical vapor deposition (PECVD) have been discussed. The use of different nitrogen-containing gases, ammonia, methylamine or nitrogen itself, combined with methane or acetylene, results in films with similar microstructures. As a general rule, the incorporation of nitrogen into the amorphous network increases with the partial pressure of the nitrogen-precursor gas at the expense of the carbon content. This increase is followed by a substantial reduction of the deposition rate. The nitrogen incorporation also reduces both the compressive internal stress and the fraction of carbon atoms in a s p ³ state of hybridization. The stability of those films when submitted to thermal annealing or to energetic ion bombardment is also discussed.