The Effect of Hydrogen on the Tribological Properties of Hydrogenated Amorphous Carbon Films

Hydrogenated amorphous carbon films were deposited on silicon substrates by using an RF PECVD. The hydrogen/methane ratio was varied from 50% to 88% to study the effect of hytdrogen in the film on the tribological properties. The friction and wear behaviors of the deposited films were investigated by ball-on-disk type wear tester. FT-IR spectra were used to characterize the structure of the films. Tribological properties of carbon films were correlated with their structure such as ratio of "polymer-like" stretching type and that of sp² bonding. The result showed that the annealing caused a decrease in the amount of wear of contacted Si₃N₄ balls and a increase in the coefficient of friction. Possible explanation for annealing effect was discussed by the hydrogen desorption.