Electropotential-stimulated wear of copper during chemical mechanical planarization

We investigated the electrochemical–mechanical wear behavior of copper during chemical–mechanical planarization (CMP). The CMP is a chemical wear process in which the mechanism is yet to be thoroughly understood. We used a non-conventional approach to apply an electro current to CMP in order to gain insight from the movement of electrons, ions, and atoms. This was possible by applying electropotential to a polisher. After the electrochemical–mechanical polishing (ECMP) was completed, the X-ray photoelectron spectroscopy (XPS) analysis was conducted. Results showed the formation of chemical reaction products, such as CuO and Cu(OH)2, which were not in an equilibrium state. Furthermore, the application of cyclic potential as well as anodic and cathodic potentials differentiated the surface quality. A new wear mechanism associated with the surface quality is proposed.