Synthesis and Evaluation of Organic Additives for Copper Electroplating of Interconnects

Copper interconnects are essential to the functionality, performance, power efficiency, reliability, and fabrication yield of electronic devices. They are widely found in chips, packaging substrates and printed circuit boards, and are often produced by copper electroplating in an acidic aqueous solution. Organic additives play a decisive role in regulating copper deposition to fill microgrooves, and micro-vias to form fine lines and interlayer interconnects. Generally, an additive package consists of three components (brightener, suppressor, and leveler), which have a synergistic effect of super-filling on electroplating copper when the concentration ratio is appropriate. Many works of literature have discussed the mechanism of super filling and the electrochemical behavior of representative additive molecules; however, few articles discussed the chemical structure and preparation of the additives. Herein, this paper focuses on the preparation method and the rapid electrochemical screening of each additive component to provide an idea for the future development of copper electroplating additives.