The Role Of Chemical Constituents In Copper Cmp Slurries

Copper chemical mechanical planarization is one of the most critical techniques for damascenes interconnect processing. The demand for copper CMP slurries that can provide high polishing rates and fewer defects at low down force has increased with the integration of copper and low-k dielectrics. This requirement warrants copper CMP more to be a chemistry-driven process rather than a mechanically dominated one. The present investigation was focused on the understanding of the removal mechanism during copper CMP using hydrogen peroxide based slurries under the influence of various pH. Ethylenediamine (EDA) and glycine (Gly) were used as complexing agents, and 3-amino-triazol (ATA) was used as inhibitor, The electrochemical process involved in the oxidative dissolution of copper was investigated by potentiodynamic polarization studies. The affected surface layers of the statically etched Cu were investigated using X-ray photoelectron spectroscopy (XPS). Atomic force microscopy was employed to study the surface planarity after CMP process