Formation of Carbon Nitride Films by the Radio-Frequency Plasma Chemical Vapor Deposition Method

Abstract

Carbon nitride films are deposited both on the cathode and anode in a CH4-N2 atmosphere by radio frequency plasma chemical vapor deposition. An increase in rf power and a decrease in gas pressure lead to an increase in the self-bias voltage, which increases ion energy and ion bombardment. The films grown on the cathode and anode definitely show different properties with or without ion bombardment under the same deposition conditions. The films produced with efficient ion bombardment have lower hydrogen content, higher electrical conductivity and greater hardness. The conductivity is affected by characteristics of the films such as the bonding state of the carbon, nitrogen and hydrogen and by the number of defects in the films. It is likely that conductivity is not dominated by band conduction but by hopping conduction. It is clear that efficient ion bombardment and ion energy during film growth are important factors in producing electrically conductive and hard carbon nitride films.