Polypyridine Leveling Agent for Flat, Defect-Free Copper Electroplating

The patent modifies the molecular structure of the leveling agent by introducing specific functional groups (carboxyl, hydroxyl, or amine groups) at defined positions relative to the aromatic ring. This structural parameter change enables the additive to simultaneously achieve defect-free filling and control surface flatness by regulating copper deposition behavior through its specific chemical structure and functional group configuration.

The patent creates a composite functional additive that combines the characteristics of both filling promoter and leveling agent in a single molecular structure. The additive integrates an aromatic core with specific functional groups that work synergistically to prevent voids and seams while simultaneously controlling excessive deposition on pattern tops, thus resolving the contradiction between reliability and surface flatness.

The patent employs an additive with specific local functional groups positioned at defined distances from the aromatic ring center. These functional groups provide localized interaction with copper ions and electrode surfaces, enabling different regions (high-density vs. low-density) to receive differentiated deposition control. This local quality approach allows accelerated filling while maintaining thickness uniformity across varying pattern densities.

The functional groups in the additive (carboxyl, hydroxyl, or amine groups) act as feedback mechanisms that sense and respond to local deposition conditions. These groups dynamically adjust copper deposition rates based on the local environment, providing negative feedback that prevents excessive thickness buildup in high-density regions while ensuring adequate filling in low-density areas, thus maintaining productivity without sacrificing uniformity.