The Effect of Copper Content on the Formation of Silicon Suboxides Phases in Cu-Si Films Obtained by Ion-Beam Sputtering

Cu-Si systems are important for a wide range of technological applications. This work is devoted to the study of the influence of copper content on the formation of silicon oxide phases in Cu-Si films obtained by ion beam sputtering. According to X-ray diffraction and ultra-soft X-ray emission spectroscopy data in a film with a low copper content of ~15 wt. % silicon is partially in an amorphous state, and partially oxidized, forming a SiO suboxide. In films with a high copper content, Cu ~65 wt. % CuSi phase is formed, which leads to the formation of phases of SiO dioxide and SiO suboxide in both near-surface and deeper layers. X-ray photoelectron spectroscopy indicates the formatio. n of predominantly silicon-oxygen tetrahedra of the Si-SiO and SiO types for Cu ~15 wt. % and more oxygen-rich Si-SiO silicon-oxygen tetrahedra for Cu ~65 wt. %, both on the surface and in deep layers of Cu-Si films.