Effects of alumina and hydrogen peroxide on the chemical-mechanical polishing of aluminum in phosphoric acid base slurry

The electrochemical behavior of aluminum in phosphoric acid base slurry was investigated under chemical-mechanical polishing (CMP) condition. The effect of alumina and hydrogen peroxide concentration on the CMP metal removal rate was evaluated. The experimental results from potentiodynamic polarization curve measurements indicated that a particle content in the range of 1–15 wt.% greatly modified the electrochemical behavior by decreasing the corrosion potential and increasing the passive current density. The results of electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) examinations showed that the passivation behavior of Al in the testing slurry was affected by hydrogen peroxide. The CMP removal rate was also a strong function of hydrogen peroxide concentration in the phosphoric acid base slurry.