The influence of leveler Brilliant Green on copper superconformal electroplating based on electrochemical and theoretical study

• • Synergistic suppressing mechanism was illustrated to explain the strong suppressing ability of Brilliant Green on copper electrodeposition. • • The strong suppressing effect of Brilliant Green was confirmed by electrochemical tests. • • Copper superconformal electrodeposition was achieved and high FP values (80.52 % to 84.38 %) with low SDT (about 28μm) was obtained in the optimized condition. • No conflict of interest exists in the submission of this manuscript. I would like to declare on behalf of my co-authors that the work described herein is original that has not been published previously and is not under consideration for publication elsewhere, in whole or in part. All the authors listed have approved the manuscript that is enclosed. Finding proper additive to achieve copper superconformal electrodeposition is significantly important. Brilliant Green exhibits excellent suppressing ability to the copper electrodeposition according to electrochemical analysis. Meanwhile, 100 mg/L was selected as the optimum value based on the convection-dependent adsorption behavior analysis of Brilliant Green. The interaction among three different additives was also investigated by applying chronopotentiometry as well as Brilliant Green compete to absorb on the cathode surface with SPS. Besides, the introduction of Brilliant Green can improve the transport of cupric ions (Cu 2+ ). The nucleation and growth of copper deposition is 3D diffusion-controlled instantaneous growth process at high overpotential but 3D diffusion-controlled mixing growth process at low overpotential. The synergistic suppressing mechanism was proposed to explain strong suppressing effect of BG on reduction of Cu 2+ and the reaction pathways was studied theoretically. Copper interconnect layer with high FP values (80.52 % to 84.38 %) was obtained with low SDT (about 28μm) after electroplating process was optimized. The surface morphology under the influence of Brilliant Green is compact and uniform and the grain size is reduced by Brilliant Green.