The investigation of carbon nitride films deposited at various substrate temperatures and N2/Ar flow ratios by vacuum cathodic arc method

Amorphous carbon nitride films have been deposited by vacuum cathodic arc method at various N2/Ar flow ratios and substrate temperatures. The properties of the films were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (IR) spectroscopy. At 200 and 400 8C, the N content could arrive at 16–18 at.% and showed the increasing tendency and then came to the saturation values with the N2/Ar ratio. While at room temperature it could be up to 31 at.% and the falling stage was even observed after the saturation. At 200 and 400 8C, from 0/50 to 50/50 sccm, the development of the aromatic cluster component was observed. In addition, there was probably some interlinked carbon backbone component in the films and the N atoms were mainly incorporated into the aromatic clusters. In the range of 150/50– 400/50 sccm, it seems that the temperature played the similar role to N2/Ar ratio in affecting the microstructure. The films developed from polymeric-like type to the type similar to amorphous carbon with the temperature at 150/50 sccm and with N2/ Ar ratio at room temperature, respectively. In addition, in the case of 400 8C with increasing N2/Ar flow ratio from 150/50 to 400/ 50 sccm or in another case of 250/50 sccm with increasing the substrate temperature from room temperature (RT) to 400 8C, the decreasing of polymeric component and then the development of aromatic component was observed. Furthermore in both cases of 400 8C and 400/50 sccm, respectively, the aromatic cluster component developed gradually. As for the film at 400/50 sccm: 400 8C, there was probably some interlinked N-containing backbone component. The chemical sputtering, which increased with the N2/Ar ratio and substrate temperature, might play an important role in deciding the N content of the films and the transferring of the microstructure. # 2003 Elsevier B.V. All rights reserved