MeV-ion beam analysis of the interface between filtered cathodic arc-deposited a-carbon and single crystalline silicon

Amorphous carbon (a-C) films were deposited on Si(1 0 0) wafers by a filtered cathodic vacuum arc (FCVA) plasma source. A negative electrical bias was applied to the silicon substrate in order to control the incident energy of carbon ions. Effects of the electrical bias on the a  -C/Si interface characteristics were investigated by using standard Rutherford backscattering spectrometry (RBS) in the channeling mode with 2.1-MeV He2+He2+ ions. The shape of the Si surface peaks of the RBS/channeling spectra reflects the degree of interface disorder due to atomic displacement from the bulk position of the Si crystal. Details of the analysis method developed are described. It was found that the width of the a-C/Si interface increases linearly with the substrate bias voltage but not the thickness of the a-C film.