Enabling AI and HPC: Defect-Free, Co-Planar Copper via fill Plating process for Advanced IC Substrates

The global IC substrate market is experiencing robust growth, projected to expand from USD 15.1 billion in 2024 to USD 37.1 billion by 2033, fueled by the rising demand for advanced semiconductor packaging solutions in artificial intelligence (AI), 5G, and high-performance computing (HPC) applications. As chip dimensions shrink and interconnect densities increase, IC substrates are evolving to incorporate wafer-level precision manufacturing techniques traditionally associated with front-end semiconductor processing. This evolution necessitates plating solutions capable of delivering ultra-fine line and space (L/S) structures, defect-free via filling, and highly planar surfaces — all critical for ensuring multilayer stack integrity and superior electrical performance.

In this study, we present an innovative copper electroplating process specifically tailored for 

advanced IC substrates, utilizing wafer-level technology principles adapted for substrate 

manufacturing. The process is optimized for embedded trench fill, simultaneous via fill, and 

through-hole plating with enhanced pattern plate capability. A bottom-up copper filling mechanism, 

driven by a finely tuned additive package—including suppressors, accelerators, and levelers—ensures uniform, defect-free filling of microvias and trenches. This approach eliminates common defects such as V-pitting, seam voids, and uneven copper deposits, while removing the need for costly and energy-intensive post-bake treatments.

To enable high-volume production with superior quality, the process is specifically designed for 

integration into High-Speed Plating (HSP) systems. HSP tools offer rapid throughput, precise current control, and uniform fluid dynamics, making them ideal platforms for advanced substrate electroplating. Leveraging HSP capabilities, the process ensures excellent via fill quality, superior co-planarity across the entire panel, and high mechanical and electrical reliability—critical attributes for AI and HPC applications.

Comparative studies show that the new plating process achieves significantly flatter pattern 

profiles and improved microvia filling compared to traditional dome-shaped plating outcomes. The 

resulting copper deposits demonstrate enhanced mechanical strength and elongation, meeting the rigorous demands of next-generation semiconductor packages.

By translating wafer-level precision into high-speed, panel-level manufacturing, this solution sets a new benchmark for IC substrate technology. It provides a scalable, efficient, and reliable pathway to meet the evolving performance and miniaturization requirements driven by the  explosive growth of AI and HPC markets.