The study of bonding composition of CNx film by thermal degradation method

Dynamic thermal degradation of amorphous carbon nitride (a-CNx) thin films was studied in N-2 and air. The films were magnetron-sputtered at two different pressures to yield various C-C and C-N ratios. Typically, the films consist of interstitial and weakly-bonded carbon-nitrogen molecules or clusters and nitrogen-substituted graphitic-carbons. The carbon and nitrogen atoms are mainly bonded ill sp, sp(2) and sp(3) configurations that may contain N charged defects. The relative amount of nitrogen-substituted graphitic-carbons is significantly increased with plasma energy. The decomposition generally occurs in two steps. The first, initiating at similar to200 degreesC in air and with apparent activation energy (E-a) of similar to111 kJ/mol, relates to the oxidation and release of interstitial and weakly-bonded carbon-nitrogen molecules. The second, starting at similar to520 degreesC and having E-a of similar to140 kJ/mol, can be ascribed to the dissociation of nitrogen-substituted graphitic-carbons. (C) 2003 Elsevier Ltd. All rights reserved.