Magnetron-sputtered carbon nitride (CNx) films

Carbon nitride (CNx) films were deposited by reactive d.c. magnetron sputtering. The structural and compositional properties of the films were characterised as a function of the deposition parameters including nitrogen partial pressure. X-ray photoelectron spectroscopy measurements showed a maximum nitrogen content of 18 at.%. The presence of C ≅ N bonds was confirmed by Raman spectroscopy, which gave a signature characteristic of disordered graphitic material with a reduction in the disorder with increasing nitrogen content. Surface roughness, as measured by atomic force microscopy, was seen to be dependent on both the substrate bias and the system pressure, however no effect of nitrogen partial pressure was evident. The films were generally amorphous, but globules or irregular-shaped surface features were also observed.