DEPOSITION OF AMORPHOUS HYDROGENATED CARBON-FILMS DUE TO HYDROCARBON MOLECULE ION-BEAM BOMBARDMENT

Carbon deposition and hydrogen codeposition are investigated as functi ons of ion energy, fluence and target temperature at normal incidence on silicon and graphite by bombardment with mass selected CH2+, CH3+, CH4+ and CD4+ molecule beams. An amorphous hydrogenated carbon layer ( a-C:H) is formed in a thickness range of 40 to 130 nm by CH3+ and CH2 bombardment up to a fluence of 3 X 10(18)/cm(2). The deposition proce ss, the re-erosion phenomenon and the H/C ratio of the a-C:H films are studied between 300 and 1100 K in the ion energy range from 0.15 to 3 keV by means of ion beam analysis and Auger Electron Spectroscopy (AE S). The experimental results are compared with TRIDYN computer simulat ion and previous experimental results of carbon sputtering by atomic H + and C+ beams in order to get a better understanding of the interacti on between hydrocarbon ions and the carbon-based wall materials in fus ion devices.