Epoxy-based Reaction Driven Low-temperature Hybrid Bonding for Next-generation HBM and 3D packaging

초록

In this study, low-temperature Cu/SiO2 hybrid bonding is enabled by the epoxy-based reaction and electroless deposition. Our strategy to achieve the low-temperature bonding is to functionalize the SiO2 dielectric layer with two different silanes of GPTMS and APTES, which can induce the epoxy ring-opening reaction and depositing Au on Cu pads. After the sequential functionalization and deposition, the resulting hybrid bonding chips are bonded by the thermocompression. As a result, two chips are completely bonded without any delamination and voids at low bonding temperature (250 °C). In this study, low-temperature Cu/SiO₂ hybrid bonding is achieved through a synergistic combination of an epoxy-based chemical reaction and electroless metal deposition. To enable this, the SiO₂ dielectric surface is functionalized with two different silanes of GPTMS and APTES, which can promote the epoxy ring-opening reactions and selective Au deposition on Cu pads. After sequential surface functionalization and electroless deposition, the chips were bonded via thermocompression. As a result, complete Cu/SiO₂ hybrid bonding was realized at a low temperature of 250?°C without any interfacial delamination or void formation. Low-temperature hybrid bonding is achieved through the strong polymerization force induced by epoxy formation, which enhances adhesion strength and enables bonding at reduced temperatures. This scalable combined method of epoxy polymerization and electroless metal deposition can be a promising approach for next-generation HBM and 3D packaging technologies. - 본 연구는 2025년도 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임(RS-2022-NR070869). Keywords: Low-temperature hybrid bonding, Electroless deposition, Epoxy polymerization, Cu?Cu interconnects, Advanced semiconductor packaging