Research progress on the action mechanism of copper electroplating additives and their coupling regulation for coating structure optimization

Copper plating technology is of great importance in the electronics industry, especially in printed circuit board (PCB) and integrated circuit manufacturing. As the market demand for high-performance, highly integrated electronic devices continues to grow, electroplating copper processes are confronted with a series of technical challenges. This paper systematically reviews the classification, functional characteristics and action mechanisms of inhibitors, accelerators and levelers during the electrodeposition process. It focuses on analyzing the individual mechanisms of key additives such as polyethylene glycol (PEG), bis(3-sulfopropyl) disulfide (SPS) and chloride ions (Cl⁻) in optimizing the coating structure by regulating interfacial adsorption configuration, inducing preferred crystal orientation and refining grain size. On this basis, the synergistic interaction mechanisms of additives in the PEG-Cl⁻-SPS ternary system and other multi-component systems are discussed in depth, revealing how dynamic competitive adsorption and alternating “inhibition-acceleration” structures synergistically regulate the microstructural evolution of copper deposition. Finally, from the perspective of structural optimization, the breakthrough directions of superfilling technology, the design strategies of novel polymeric additives and the future development trends of intelligent regulation of process parameters are summarized, aiming to provide theoretical basis and technical support for the further optimization of copper electroplating technology.