Amorphous carbon nitride (CN) films have been deposited onto Si(100) substrates by reactive sputtering of a graphite target in a purl N-2 ambient. A modified cylindrical DC magnetron plasma was used as a sputter deposition source and the effects of substrate DC self-bias voltage caused by RF bias on film properties were investigated. X-ray photoelectron spectroscopy (XPS) spectra of N Is and C Is electron confirmed the existence of multiple bonding states for carbon and nitrogen (sp(2) and sp(3)) in the film. Fourier transform infrared (FTIR) spectroscopy studies showed a systematic variation in spectra by a DC self-bias voltage. Raman spectra revealed two peaks corresponding to G band (1580 cm(-1)) and D band(1370 cm(-1)). The ratio of integrated intensities of D and G band (I-D/I-G) increased with DC self-bias voltage, suggesting increased disorder by the ion bombardment on growing film. Variation in the morphology of CNx films deposited at different bias voltage was examined by scanning electron microscopy (SEM).