Electrochemical Action of FA/O II Chelating Agent and H2O2 on Copper Film in the Polishing Process

Abstract

The role of chelating agents and H2O2 in chemical mechanical planarization was investigated by electrochemical measurements. First, the open circuit potential, polarization curves and cyclic voltammetry curves of the slurry were tested when it contained FA/O II chelating agent by concentrations of 0%, 0.5%, 1%, 3% and 5%, respectively, and at the H2O2 concentration of 0%, 0.5% and 2% in the slurry, respectively. The results showed that when the concentration of FA/O II chelating agent was 0.5% and the concentration of H2O2 was 0.5%, the open circuit potential moved towards the negative, and the electrochemical anodic reaction was enhanced. At this point, the polarization curve showed that the oxidation was obviously strengthened. The cyclic voltammetry curves showed that when the concentration of H2O2 was 0.5%, with the increase of the concentration of chelating agent, the anodic peak current increased, the electrochemical anodic reaction enhanced. The open circuit potential and polarization curves obtained consistent results. Therefore, when the concentration of FA/O II chelating agent was 0.5% and the concentration of H2O2 was 0.5%, the excessive corrosion could be avoided, and the selectivity of removal rate of copper surface would be improved, and the planarization efficiency could be improved.