CHARACTERIZATION OF NITROGEN IN A-CNX THIN-FILMS BY GAS EFFUSION SPECTROSCOPY

The evolution and characterization of nitrogen N-2 in amorphous CNx (a -CNx) have been studied by using gas effusion spectroscopy. In gas eff usion spectra for a-CNx thin films, N-2 evolution peaks are found near 200, 400, 600 and 700 degrees C. The N-2 peak near 200 degrees C disa ppears after hydrogen plasma treatment. In the gas effusion spectrum o f H-2 for a sample treated by hydrogen plasma, a very small shoulder w ould be found near the temperature of the H-2, evolution peak in chemi cal vapor deposited diamond. By ultra-violet irradiation, the amplitud es of the N-2, evolution peaks above 400 degrees C increase and the x = N/C ratio obtained by X-ray photo-electron spectroscopy increases fr om 0.5 to 0.7. From these results and comparison with other works, the origin of the N-2 evolution peaks near 200 and 400 degrees C could be estimated as N-2, related to a graphite-like structure and N-2, from C=N, respectively, and either N-2, evolution near 600 degrees C or nea r 700 degrees C, or both, could be related to C=N bonds. (C) 1998 Else vier Science B.V. All rights reserved.