Application of Low-Temperature Hybrid Bonding Process via Selective Metal Deposition Method

초록

A low-temperature Cu/SiO2 hybrid bonding strategy is demonstrated through electroless deposition (ELD) of ultrathin metals, enabling sub-micrometer-pitch interconnections for three-dimensional (3D) integration. Gold (Au), platinum (Pt), and tin (Sn) interlayers with thicknesses of 10?40 nm are selectively deposited on 500 nm Cu pads via a solution process, leaving the adjacent SiO2 dielectric unaffected. Bonding is achieved by vacuum pre-bonding at 120 °C and annealing at 250 °C, yielding strong Cu?Cu diffusion and void-free interfaces. The ELD metal layers enable precise interface chemistry control, while complementary silane treatment ensures reliable dielectric bonding. This process thus offers a scalable low-temperature route for fine-pitch hybrid bonding and a promising pathway toward next-generation ultra-dense 3D integrated semiconductor packaging. - 본 연구는 2025년도 정부(교육부) 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임(RS-2022-NR070869).? Keywords: Hybrid bonding, Cu?Cu metallic bond, Electroless deposition, Low temperature bonding, Advanced packaging