OES STUDY OF PLASMA PROCESSES IN DC DISCHARGE DURING DIAMOND FILM DEPOSITION

A systematic study has been performed of optical emission spectra from d.c. glow discharge during diamond film deposition. The emission inte nsity within the region 400-700 nm was found to be a function of metha ne concentration and interelectrode position. The experiments were car ried out under hydrogen pressure 160 Torr and methane concentration 0% -3%. The optical emission had a different character for different disc harge regions (anode and cathode regions, plasma volume). The optical spectra observed were also essentially different from the flame and je t arc emission spectra. The most intensive lines in our experiments we re emitted by hydrogen atoms, H(alpha) and H(beta). Using a ratio of t hese lines the electron temperature in CH4 + H2 plasma was estimated. The R-branch of the H-2 molecular (G1SIGMA(g+)-B1SIGMA(u+) (0-0) band in the emission spectra near lambda = 463 nm and vibration structures in the emission spectra of the radical C2 (d3PI(g-)a3PI(u)) near lambd a = 515 nm were also examined. These data were used to determine a gas temperature.