Detection of CHx bonds and sp2 phases in polycrystalline and ta-C:H films from Raman spectra excited at 325 nm

The Raman spectra excited at 325 nm of polycrystalline diamond films show the specific sp(2) C broad bands of ta-C:H. The spectra of both types of films also exhibit the bands around 3050 and 2960 cm(-1) from sp(2) CH aromatic and sp(3) ch(3) bonds respectively. Therefore, the grain boundaries of polycrystalline films contain ta -C:H zones. Additional structures around 2830 and 2880 cm(-1) can be distinguished on the Raman spectra of the polycrystalline films. Most of the stretching vibrations from the CHx bonds appear in these 325 nm-Raman spectra. Therefore, they appear convenient for qualitative studies of the CH., bonds in any carbon film. (c) 2005 Elsevier B.V. All rights reserved.