Thin TaC layer produced by ion mixing

Ion-beam mixing in C/Ta layered systems was investigated. C 8nm/Ta 12nm and C 20nm/Ta 19nm/C 20nm layer systems were irradiated by Ga+ ions of energy in the range of 2–30keV. In case of the 8nm and 20nm thick C cover layers applying 5–8keV and 20–30keV Ga+ ion energy, respectively resulted in strongly asymmetric ion mixing; the carbon was readily transported to the Ta layer, while the reverse process was much weaker.

Because of the asymmetrical transport the C/TaC interface remained sharp independently from the applied fluence. The carbon transported to the Ta layer formed TaCx. The stoichiometry of the carbide produced varied along the depth. The TaCx layer contained implanted Ga, the concentration of which decreased with increasing depth.

The thickness of the TaCx layer could be tailored by the ion fluence and energy making possible to produce coating layer of desired thickness.