Deposition of carbon nitride films by filtered cathodic vacuum arc combined with radio frequency ion beam source

Abstract

Atomically smooth carbon nitride films were deposited by an off-plane double bend filtered cathodic vacuum arc (FCVA) technique. A radio frequency nitrogen ion source was used to supply active nitrogen species during the deposition of carbon nitride films. The films were characterized by atomic force microscopy (AFM), XPS and Raman spectroscopy. The internal stress was measured by the substrate bending method. The influence of nitrogen ion energy (0–1000 eV) on the composition, structure and properties of the carbon nitride films was studied. The nitrogen ion source greatly improves the incorporation of nitrogen in the films. The ratio of N/C atoms in the films increases to 0.40 with an increase in the ion beam energy to 100 eV. Further increase in the ion beam energy leads to a slight decrease in the N/C ratio. XPS results show that nitrogen atoms in the films are chemically bonded to carbon atoms as CN, CN, and CN bonds, but most of nitrogen atoms are bonded to sp2 carbon. The increase in nitrogen ion energy leads to a decrease in the content of nitrogen atoms bonded to sp2 carbon, and an increase in the content of nitrogen atoms bonded to sp3 and sp1 carbon. Raman spectra indicate an increase in the sp2 carbon phase in carbon nitride films with an increase in nitrogen ion energy. The increase in sp2 carbon fraction is attributed to the decrease in internal stress with increasing nitrogen ion energy.