Microstructures and properties of CN films grown by dielectric barrier discharge plasma enhanced chemical vapor deposition

The carbon nitride films were grown by dielectric barrier discharge plasma enhanced chemical vapor deposition (DBD-PECVD) with gas-mixtures of CH4/N2, C2H2/N2and C2H4/N2, respectively, on silicon substrates. The microstructures and properties of the CN films were characterized with Fourier transform Infrared spectroscopy (FTIR), Raman spectroscopy and atomic force microscopy (AFM). The influence of the film growth conditions on the film quality was studied. Diamond-like structures and C-N bonds were observed in the films. The results show that the type of the gas mixtures and the discharge pressure strongly affect the deposition rate and the surface roughness. For example, the film deposited in the CH4/N2gas mixture shows the lowest deposition rate and the least H contents of the three gas mixtures, whereas the one in the C2H2/N2shows the highest deposition rate. The CN films deposited with CH4/N2gas mixture are smoother than those deposited with both C2H2/N2and C2H4/N2, gas mixtures.