Effect of arginine-based cleaning solution on BTA residue removal after Cu-CMP

In chemical mechanical polishing (CMP) process, surface defects and contamination will be introduced on the wafer surface due to interfacial chemical reactions and abrasive particles, especially the presence of organic contaminants, which can form a film to prevent the cleaning solution from contacting the wafer surface and seriously affecting the subsequent cleaning process. Benzotriazole (BTA) is the most typical corrosion inhibitor for copper CMP, which results in hydrophobic surface of copper and directly affects the removal and drying of particles. In this paper, FA/O II chelating agent and arginine were used as main cleaning agents of arginine-based alkaline cleaning solution, and polyethylene glycol octylphenyl ether (Triton X-100) nonionic surfactant was added as auxiliary wetting agent to study the removal of BTA. In the framework of density functional theory (DFT) generalized gradient approximation (GGA), the quantum chemical parameters of arginine molecule were calculated by using the B3LYP correlation function to predict the reaction sites of strong interaction between arginine molecule and copper surface. Simultaneously, the effects of concentration changes of arginine and Triton X-100 on BTA removal were characterized by means of contact angle measurement, electrochemical methods and atomic force microscopy (AFM). The results show that when the composition of cleaning agent was 200 ppm FA/O II and 200 ppm ammonia, and 1800 ppm Triton X-100, the contact angle of the copper surface was decreased by 42.5 degrees, and the roughness value was at least 2.03 nm, which exhibited that excellent cleaning performance of the cleaning solution can effectively remove BTA and other micro-defects.