Electronic properties, bonding structure and mechanical behaviours of a-CNx: Si (: B) thin films

Abstract

The electronic properties, bonding structure and mechanical behaviours of amorphous carbon nitride (a-CNx), silicon doped a-CNx (a-CNx:Si) and boron doped a-CNx (a-CNx:B) thin films alloys were studied by the C K-edge, N K-edge x-ray absorption near edge structure (XANES) and valence band photoelectron spectroscopy (VB-PES). The a-CNx:Si and a-CNx:B shows higher Young’s modulus compare to a-CNx thin film that are due to increase of carbon sp3-hybridized cluster in C and N K-edge XANES spectra. We have observed from the C and N K-edge XANES spectra that the formation of different carbon, nitrogen, silicon and boron bonding with carbon in the a-CNx:Si(:B) film structure. VB-PES spectra showed that the p-σ band became more intense than the p-π band upon the addition of silicon and boron in a-CNx film structure, which confirmed the role played by the σ bonds in controlling the electronic structure of a-CNx films and hence their mechanical behaviour. These films could be very useful in the surface coating technology.