The effect of the gas composition in N2-H2, gas mixture plasma on the growth rate of titanium nitride layers was investigated by optical emission spectroscopy (OES), microscopic observation, and X-ray diffractometry. The growth rate of nitride layers was enhanced by hydrogen addition, which was the highest at 50vol.%N2-50vol.%H2. The results of the spectroscopic measurements and microscopic observations indicate that NH radical intensity is correlated with the growth rate of nitride layers. It is suggested that NH radical plays the most significant role during nitriding process. XRD analysis shows that the compound layers consists of TiN and Ti2N. In the diffusion layers, acicular textures were observed by microscopic observation.
