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

• Published in: Applied surface science 2016-10, Vol.384, p.505-510
• Main Authors: Cho, Byoung-Jun, Shima, Shohei, Hamada, Satomi, Park, Jin-Goo
• Format: Article
• Language: English
• Subjects: Chemical mechanical planarization (CMP); Cleaning; Complex formation; Copper; Corrosion inhibition; Corrosion inhibitors; Cu-BTA complex; Electrical equivalent circuit modeling; Electrochemical impedance spectroscopy; Ellipsometry; Oxides; Planarization; Surface chemistry
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2016.05.106

•The effect of Cu surface on Cu-BTA complex formation was studied.•Cu treated with acetic acid showed higher contact angle and higher polarization resistance compared to the other surfaces.•XPS measurements confirm the formation of CuO on Cu when it is treated with H2O2.•Cu-BTA complex is highly affected by Cu surface condition and it should be considered during Cu CMP and post-Cu CMP cleaning process. 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.