Quantitative Adhesion Properties and Interfacial Behavior of SiCN Barrier Layer and Cu Film

Adhesion of the SiCN barrier layer and Cu film interface is one of the important characteristics that reflect the interfacial structure. NH3 plasma treatment of the Cu surface is a well-known way of improving adhesion. The results of X-ray reflectivity (XRR) and X-ray photoelectron spectroscopy (XPS) depth profiles indicate that the plasma treatment imparts a difference to the formation of the interface with SiCN. Adhesion properties are regarded as fracture energies measured by double cantilever beam (DCB) and 4-point bending (4PB) techniques. The influence of the NH 3 plasma treatment of the Cu surface on adhesion is quantitatively discussed. The treated samples showed approximately twice the fracture energy of the non-treated samples. After 4PB and DCB measurements, fracture surfaces were investigated by XPS and atomic force microscopy (AFM). The formation of a N-Cu chemical bond on the Cu surface was enhanced as a result of removing oxygen by the plasma treatment. N-Cu chemical bonding contributes substantially to better SiCN/Cu interfacial adhesion.