Structure, electrical conductivity and Hall Effect of amorphous Al–C–N thin films

Abstract

A series of Al–C–N thin films with different Al contents were deposited on Si (100) substrates by closed field unbalanced reactive magnetron sputtering in the mixture of argon and nitrogen gases. Their phase configurations and structures were subsequently investigated by X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy measurement, cross-sectional field emission scanning electron microscopy and high-resolution transmission electron microscopy, while their electrical conductivities and Hall Effects were studied by physical property measurement system. The results indicated that all deposited Al–C–N thin films were amorphous. There were three bonds, C–N, C–C and Al–N, in Al–C–N thin films irrespective of Al content. Increase of Al content increased the amount of Al–N bonding at the cost of that of C–C bonding. Higher Al content led to less sp 2 C–C bonding. The films with low Al content were essentially P-type semiconductor. Increase of Al content increased the electrical resistance, making the film gradually transform to insulation, which was attributed to increase of band gap. Hall coefficient was increased with increase of Al content, which was contributed to decrease in concentration and mobility of hole in the films.