Fine-pitch Cu?Cu Interconnection by Electroless Deposition of Various Metals for Advanced Packaging

초록

Fine-pitch Cu?Cu interconnection was successfully achieved by selective metal deposition via electroless deposition. Electroless deposition (ELD) solutions were prepared by optimizing the metal precursor, reducing, and complexing agent to ensure uniform metal coating. The successful thin metal layer on the Cu pad was investigated by SEM and OM analysis. Metal-ELD-treated Cu/SiO2 hybrid bonding chips were bonded using a two-step process.. In particular, Au-ELD HB chips exhibited the most reliable bonding with narrow gap of 10 nm at low temperature due to the superior diffusion characteristics of noble Au metal. These results demonstrate the importance of metal selection in fine-pitch Cu?Cu interconnection, offering a practical and scalable solution for next-generation advanced packaging technologies. -본 연구성과물은 2025년도 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임 (RS-2024-00464661). Keywords: Electroless deposition, Fine-pitch interconnection, Low temperature, Hybrid bonding, Advanced packaging.