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/SiO2 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 SiO2 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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