Abstract: Carbon nitride (CN) thin films were prepared on Si (100) substrates by hot filament assisted RF plasma chemical vapor deposition. X-ray diffraction spectra indicate that the obtained CN films contain crystalline β-C3N4 and α-C3N4 as well as an unknown structural phase. Obvious absorption peaks from C-N, C＝N and C≡N bonds were observed in Fourier transform infrared absorption spectra of the films, the respective wavenumbers are centered at 1237, 1625 and 2191 cm-1. Some crystalline grains of 1-2 μm in size with a hexagonal cross section were seen in the films by scanning electron microscopy. The maximum hardness of the film deposited at optimum conditions is as high as 72.66 GPa.

Key words: Carbon nitride (CN) thin films were prepared on Si (100) substrates by hot filament assisted RF plasma chemical vapor deposition. X-ray diffraction spectra indicate that the obtained CN films contain crystalline β-C3N4 and α-C3N4 as well as an unknown structural phase. Obvious absorption peaks from C-N, C＝N and C≡N bonds were observed in Fourier transform infrared absorption spectra of the films, the respective wavenumbers are centered at 1237, 1625 and 2191 cm-1. Some crystalline grains of 1-2 μm in size with a hexagonal cross section were seen in the films by scanning electron microscopy. The maximum hardness of the film deposited at optimum conditions is as high as 72.66 GPa.