DETERMINATION OF THE OPTIMAL ENERGY-RANGE FOR OBTAINING DIAMOND-LIKE FILMS BY ION-IMPLANTATION

Pure films of carbon were grown by implanting C+ ions at energies in the range 0.1-2 keV in various substrates. Analysis of their compositions by various ion beam interactions showed that there was little mixing with the substrate layers and radiation-enhanced diffusion in the films, and the impurity content decreased with decreasing ion energy. On the basis of spectroscopic investigations of optical absorption and soft X-ray emission, we also established that the percentage of diamond-like carbon (DLC) increased monotonically with ion energy. DLC was only obtained during the preliminary stages of implantation in silicon or SiC at energies below 1 keV, because of their catalytic effect on the sp3 hybridization of carbon atoms. Films formed at 2 keV exhibited similar properties to those grown by laser-plasma deposition and contained about 75% diamond microcrystals. They were also more diamond-like than films grown by sputtering processes.