Investigation of cu-BTA complex formation during Cu chemical mechanical planarization process

Abstract

The effect of Cu surface conditions on Cu-BTA complex formation was investigated using contact angle, electrochemical impedance spectroscopy, spectroscopic ellipsometry and XPS measurements which is of interest to Cu Chemical Mechanical Planarization (CMP) process. During Cu CMP process BTA is widely used as a corrosion inhibitor, reacts with Cu and forms a strong Cu-BTA complex. Thus, it is very essential to remove Cu-BTA complex during post-Cu CMP cleaning process as Cu-BTA complex causes severe problems such as particle contamination and watermark due to its hydrophobic nature. In this report, the Cu-BTA complex formation at various Cu surfaces (as received, pure Cu and Cu oxide) was investigated in order to understand its adsorption reaction and develop effective post-Cu CMP cleaning process.