ANALYSIS OF DIAMOND PHASE IN HYDROGENATED HARD CARBON-FILM USING RADIO-FREQUENCY PLASMA-ETCHING

The hydrogenated hard carbon films prepared in CH4 radio frequency (rf) discharge, have been examined to characterize the film structure by means of several spectroscopic measurements combined with CF4 rf plasma etching. The CF4 plasma etching can selectively remove the amorphous phase with graphite structure, and can retain the diamond structure in the film. After the CF4 plasma etching for a long time, cylindrical structures and/or particles were formed on the substrate. The top of the cylindrical structure or the particle was diamond, and the bottom part was the Si substrate. It was confirmed that most of the components in the hard carbon film is amorphous phase, and the diamond phases exist at the interface between the film and the substrate.