Energetic ion scattering analysis and glow discharge optical spectrometry characterization of amorphous hydrogenated carbon films elaborated by PACVD

Abstract

Amorphous hydrogenated carbon films (a-C:H) were deposited by PACVD on stainless steel substrates. The properties of these films can vary with the elaboration of the conditions, and therefore with the composition. Here, the films were quantitatively determined by energetic alpha particle scattering using two different methods: elastic recoil detection (ERD) for hydrogen analysis; and nuclear backscattering spectrometry (NBS) for carbon and oxygen analysis. Concurrently, the same samples were investigated by glow discharge optical spectrometry (GDOS), a method which gives information on all the elements of the periodic table. Nuclear method investigations showed that the a-C:H films were composed of two layers: the film itself of constant stoichiometry and a hydrogen depleted surface layer. They showed too a strong hydrogen diffusion inside the substrate and the presence of oxygen at the interface. GDOS profiles characterized the film, the film/substrate interface and the substrate. Particularly, Al presence at the interface and in a part of the deep-lying layer of the film was detected. This results from cathode sputtering during the elaboration process.