Investigation of Cu-BTA Complex Formation and Removal on Various Cu Surface Conditions

The effect of Cu surface conditions on Cu-BTA complex was investigated using ex-situ electrochemical impedance spectroscopy method. Cu-BTA complex is generated during Cu CMP process because BTA which is the most common corrosion inhibitor in Cu CMP slurry react with Cu and form a strong complex. Then it is very important to remove Cu-BTA complex during post-Cu CMP cleaning because Cu-BTA complex cause severe problem such as particle contamination and watermark due to its hydrophobic characteristic. The Cu-BTA complex formation at various Cu surfaces was investigated to understand its behavior, so the effective development will be possible in post-Cu CMP cleaning process.