Influence of Chemical Bonding States on Electrical Properties of Amorphous Carbon Nitride Films

The electrical properties of amorphous carbon nitride (a-CNx) films have been investigated in terms of the nitrogen concentration (N/C) and chemical bonding states in the films. The films were deposited by the reactive rf magnetron sputtering method. Nitrogen concentration and chemical bonding states in the films were controlled by regulating the deposition temperature. C-C networks in the films changed to those having a graphite like structure with decreasing N/C, as deduced by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). In addition, the N-sp(2)C bonding state becomes more predominant. These results indicate the contributions of the N-sp(2)C component to the decrease in electrical resistivity and increase in photoconductivity. (C) 2012 The Japan Society of Applied Physics