A NEXAFS CHARACTERIZATION OF ION-BEAM-ASSISTED CARBON-SPUTTERED THIN-FILMS

Thin carbon films were deposited by sputtering with various species by means of the technique of dynamic ion mixing (DIM). Transmission elec tron microscopy experiments reveal that the films are amorphous and co ntain contaminants, mainly oxygen. Density values are determined by gl ancing X-ray reflectometry. Friction and wear resistance measurements have been accomplished. Near-edge X-ray absorption fine structure (NEX AFS) experiments are performed at both CK and OK edges. The CK edge NE XAFS data for a film obtained with DIM and an argon-methane mixture fi lling the sputtering source show a strong peak that is attributed to C -H and O=C-OH bonds, while the number of sp(2)-hybridized carbon sites is quite small. More damped features are observed for a film deposite d without DIM when an argon-hydrogen mixture is used. However, the num ber of sp(2)-hybridized carbon sites is then greater. When DIM is used , we observe in the NEXAFS spectrum that the high energy ion irradiati on induces hydrogen release. A correlation of the NEXAFS with the wear behaviour is suggested.