Investigation of the structure and phase composition of Cu-Si films obtained by ion beam sputtering

In this work, the structure, phase composition and electronic structure of Cu-Si films with different copper content (from 15 to 68 wt.%) obtained by ion beam sputtering were studied by X-ray diffraction and ultra-soft X-ray emission spectroscopy. It was found that when Cu-Si films have a low copper content (~15 wt.%), the phases of 𝝲-Cu5Si and amorphous silicon a-Si are formed. Increasing the Cu content to up to 68 wt.% leads to the formation of the phases 𝞰-Cu3Si and 𝞰''-Cu3Si, as well as partial oxidation of copper with the formation of Cu2O oxide, while significant changes in the electronic structure of the valence band are observed as a result of the interaction of copper d-electrons and silicon s,p-electrons. An increase in the copper content in the composition of Cu-Si films from ~15 wt.% to ~68 wt.% is accompanied by a decrease in resistivity from ~1*10-3 to ~3*10-4 ohms *cm.