Emission spectra from a DC plasma discharge of nitrogen with a graphite cathode used for deposition of CNx layers were investigated in the visible range 350-900 nm. The spectra recorded at low and high resolution from both the negative glow and the positive column of the discharge were studied separately. All spectra are dominated by neutral and ionized N2 emission. In the positive column the violet band of the cyanogen (CN) radical was identified and analyzed for vibrational structure. From a computer simulation of the rotationally resolved violet band, vibrational temperatures were derived and found to be in the intensity distribution for the v = 0, 1 and 2 levels from thermal equilibrium. In the negative glow the strong N2+ features completely mask the spectral region of the violet band of CN. Conclusions were drawn concerning the CN formation by chemical sputtering, and the role of CN radicals in the formation of polymeric CNx layers of 1:1 = C:N stoichiometry.
|Number of pages||7|
|Journal||Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy|
|Publication status||Published - Mar 2000|
ASJC Scopus subject areas
- Analytical Chemistry
- Atomic and Molecular Physics, and Optics