Ultraviolet (UV) and visible Raman spectroscopy were used to study a-C:H:N films deposited using ECR-CVD with a mixed gas of CH4 and N,. Small percentage of nitrogen from 0 to 15% is selected. Raman spectra show that C equivalent to N bonds can be directly observed at 2220 cm(-1) from the spectra of visible and UV Raman. UV Raman enhances the sp(1) CN peak than visible Raman. In addition, the UV Raman spectra can reveal the presence of the sp(3) sites. For a direct correlation of the Raman parameter with the N content, we introduced the G peak dispersion by combining the visible and UV Raman. The G peak dispersion is directly relative to the disorder of the sp(2) sites. It shows the a-C:H:N films with higher N content will induce more ordered sp(2) sites. In addition, upper shift of T position at 244 nm excitation with the high N content shows the increment of sp(2) fraction of films. That means the films with high N content will become soft and contain less internal stress. Hardness test of films also confirmed that more N content is with less hardness. (C) 2007 Elsevier B.V. All rights reserved.