Characteristics of diamondlike carbon thin films produced by DC hollow cathode (DCHC) glow discharge in Ar/CH/sub 4/ plasmas

Summary Form only given, as follows. Diamondlike carbon thin films were produced by a plasma-enhanced chemical vapor deposition in a pinhole-type, hollow-cathode, DC glow discharge. The operating parameters were as follows: gas pressure from 0.01 to 10.0 mbar, discharge power from 0.1 to 20.0 W (with a discharge tube cross-sectional area of 3.14 cm/sup 2/), and concentration of methane in argon of up to 3% (atomic). Two discharge modes were observed: normal glow discharge and cathode glow discharge. The thin films produced under each discharge mode were studied and compared. X-ray diffraction measurements indicated that the films were composed of amorphous carbon, graphite, diamond, and a small amount of hydrogenated amorphous carbon. Infrared absorption showed the presence of C-H (sp/sup 3/) bonds and diamond in the films. The optical bandgap of the films is a nonlinear function of the film thickness, and its value ranges from 1.4 to 2.0 eV. Although the cathode was made of aluminum and titanium, Auger spectra showed no presence of either Al or Ti; argon is also absent from the films produced.<>