Chemical bonding of magnetron-sputtered copper on PECVD amorphous SiCOF film

The interactions between magnetron-sputtered Cu and PECVD amorphous SiCOF film have been studied via Auger electron spectroscopy (AES), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), etc. At the initial sputtering deposition of copper, Cu(II) is formed, then Cu(I) appears, and Cu(0) grows finally. This is likely attributed to high energetic copper atoms or clusters penetrating into the SiCOF film and cleaving SiO bonds. Additionally, the annealing at 400 °C in high pure N2 leads to the formation of Cu2O phase at the full expense of Cu phase, subsequently, CuO phase comes into being together with a decrease in Cu2O phase after annealing at 500 °C. Possible reason is that annealing at different temperatures causes a special ratio of Cu/O in some special diffusion area, which determines the formation of reactive production between Cu and SiCOF. Furthermore, CCu bond is not formed during sputtering deposition of copper, and even after the annealing.