Presentation Information
[8a-P09-2]Oxide-Based and Electroless Cu seeding on Glass Substrates Enabled by Liquid Phase Deposition
〇(D)Jiseok Lee1, Taeho Lim2, Jae Jeong Kim1 (1.Seoul National Univ., 2.Soongsil Univ.)
Keywords:
Cu electroless deposition,Glass,Metal oxide
As semiconductor packaging continues to pursue higher chip performance, the miniaturization of interconnects has intensified warpage issues in conventional glass-fiber-reinforced epoxy substrates. Warpage, the three-dimensional deformation of substrates, causes reliability problems such as solder defects and misalignment. This is due to the high CTE and low Young’s modulus of epoxy. To address this, glass is being explored as an alternative due to its silicon-compatible CTE and higher modulus. As stacked structures like high-bandwidth memory are integrated, substrate thinning has become critical, further increasing warpage risk and highlighting the value of glass. However, glass's low surface roughness and the presence of high-aspect-ratio through-glass vias make conventional sputtered Cu seed layers inadequate. Thus, electroless deposition (ELD) is being studied with various pretreatment strategies. This study aims to form uniform Cu seed layers on glass via liquid phase deposition (LPD), which generates oxide films from metal fluoride complexes. Tin oxide (SnOX) was used to enable Cu ELD without Sn sensitization before Pd activation—a strategy reported in literature and reconfirmed here. The optimal F/Sn ratio was determined via surface roughness and Pd particle analysis. Other oxides are also under investigation.