Influence of pH, immersion time, and benzotriazole concentration on copper corrosion in citric acid based slurries

Copper corrosion in citric acid based slurries with or without benzotriazole (BTA) was investigated as a function of the slurry pH, immersion time and BTA concentration by static etching and electrochemical experiments. The chemical composition of the corroded surface was determined using X-ray photoelectron spectroscopy (XPS). The static etching rate of copper in a H2O2+citric acid+BTA slurry was lower than that in a H2O2+citric acid slurry at pH 4.4–8. When the pH of the slurry was >8 or <4.4, the results were reversed and the static etching rate of copper increased when BTA was added to the H2O2+citric acid slurry. The inhibitory effect of BTA in the H2O2+citric acid slurry at pH 6 increased with the increasing immersion time of the copper. The corrosion current density of copper gradually decreased with increasing BTA concentration in slurry.