SPUTTERING OF CARBONIZED MATERIALS BY 1 KEV AR-IONS

The sputtering of hydrogenated or deuterated amorphous carbon layers (a-C:H) by argon ions (500-1700 eV) has been investigated by means of laser-induced fluorescence, which was used to detect atomic carbon, hydrogen and deuterium in front of the target. In order to keep the total amount of sputtered particles low, the ion source has been pulsed with 30-100-mu-s duration and 4 Hz repetition rate. A comparison between a-C:H layers and graphite showed that the sputtering yield and the velocity distribution of the C-atoms are equal within the experimental errors (+/- 15%). During the bombardment of an a-C:H layer, atomic hydrogen was also detected. A Thompson distribution with a surface energy of about 1 eV could be fitted to the velocity profiles of both atomic hydrogen and deuterium. For the D-atoms a strong transient effect of the sputtering yield was observed. For H-atoms this effect was reduced, probably by absorption of residual water vapour.