Distribution of carbon in polycrystalline copper surfaces treated by methane plasma immersion ion implantation

Copper substrates with rather large grains (dimensions of some mm) treated by pulsed methane plasma immersion ion implantation exhibit a laterally inhomogeneous carbon distribution. Areas with high carbon X-ray intensity in electron probe microanalysis coincide with thicker carbon containing layers as seen in sputter depth profiling via secondary ion mass spectrometry. The distribution of carbon within the surface depends not only on the treatment time and pulse repetition rate but also on the orientation of the individual copper grains.