Physical properties of carbon nitride films synthesized using atomic transport reactions

Inductively coupled plasma chemical vapour deposition (ICP–CVD) has been used for the preparation of thin CNx films from a solid carbon source (at floating potential) and a nitrogen plasma. Volatile CN species generated via atomic transport reactions are the film forming particles. The deposited layers have a rather smooth surface; their deposition rate and thickness, respectively, depend on the substrate position due to a gradient in the precursor species concentration. The nitrogen fraction is at about 50% and exhibits almost no dependence on the deposition parameters. Emphasis was placed on a detailed study of the bonding structure by different analytical techniques. Based on these investigations, a probable structure of the CNx films is proposed. Since no identification of tetragonally bonded carbon atoms was found, it is supposed that the bonding network is composed of imine-like units and only to a small part of nitrile-type elements. The films are insulating with resistivity of up to 1011 Ω cm.