X-ray photoelectron spectroscopy and X-ray-excited Auger electron spectroscopy studies of the initial deposition of hydrogenated amorphous carbon

Abstract

The initial layers and the film-substrate interface of hydrogenated amorphous carbon films obtained by low pressure multipolar methane-plasma-assisted deposition on crystalline Si have been studied by angle-resolved X-ray photoelectron spectroscopy and X-ray-excited Auger electron spectroscopy as a function of the ion deposition energy. Nuclear reaction analysis and elastic recoil detection analysis were also used to complete the analysis. The rate of growth, the H content and the sp 3 concentration decrese with increasing energy of ions impinging on the substrate, producing from polymer-like films (less than 400 eV) to “diamond-like” films (above 400 eV). The H and sp 3 concentrations decrease also during deposition. The film-substrate interface also varies with the energy of the ions. Either the original native oxide, 10 Å thick, is left almost unmodified for polymer-like films or an oxicarbide SiO 1.2C 0.4 about 50 Å thick is formed for “diamond-like” films.