Interfacial bonding effects of various silane treatments for dielectric layers in hybrid bonding and 3D packaging technology

초록

A silane-assisted surface functionalization strategy was employed to enhance the interfacial bonding performance of Cu/SiO<inf>2</inf> hybrid bonding (HB) for advanced semiconductor packaging applications. A series of silane precursors with varying alkyl chain lengths and terminal functional groups were applied to selectively modify the SiO<inf>2</inf> dielectric surface, promoting strong dielectric–dielectric adhesion while preserving Cu–Cu bonding regions. Among the tested silanes, (3-aminopropyl)triethoxysilane (APTES) exhibited the most favorable bonding characteristics by introducing hydrophilic amine groups that facilitate hydrogen bonding and subsequent siloxane crosslinking. The bonding behavior was evaluated by cross-sectional FE-SEM, FT-IR spectroscopy, contact angle measurements, AFM, EDS elemental mapping, and die shear tests. The APTES-treated HB chip achieved the highest bonding strength of 3.2 MPa and exhibited cohesive fracture behavior and void-free dielectric interfaces, whereas long-chain alkyl silanes resulted in reduced adhesion due to increased hydrophobicity and surface roughness. These results confirm that surface functionalization using short-chain silanes significantly improves interfacial bonding at low-temperature (250 °C) without damaging surrounding components. This study presents an applicable and thermally efficient route for enabling fine-pitch HB, emphasizing the importance of silane selection for reliable low-temperature integration in 3D semiconductor packaging. © 2025 The Author(s)

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