About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Electronic Packaging and Interconnection Materials IV
|
| Presentation Title |
Effect of Grain Structure on Low-Temperature Ag-Cu Heterogeneous Direct Bonding Without CMP |
| Author(s) |
hui-yi hsiang, Chun-Chieh Huang, Fan-yi Ou Yang |
| On-Site Speaker (Planned) |
hui-yi hsiang |
| Abstract Scope |
Low-temperature metallic direct bonding is critical for advanced 3D packaging. This study investigates the influence of grain structure on CMP-free Ag–Cu heterogeneous bonding. Ag and Cu films with nanocrystalline (NC), nanotwinned (NT), and coarse-grained (CG) structures were deposited by magnetron sputtering and bonded at 250 °C without Chemical Mechanical Planarization. NC films showed the best performance, achieving a bonding ratio of 91.4% and a shear strength of 31.8 MPa. Their superior bonding was attributed to a smoother as-deposited surface and higher stored energy. During thermal bonding, rapid grain growth and enhanced grain-boundary diffusion promoted interfacial void elimination and produced a robust interface. In contrast, NT and CG films exhibited inferior bonding because of their lower driving force for microstructural evolution. These results confirm that grain structure strongly governs CMP-free Ag–Cu bonding and highlight nanocrystalline microstructure engineering as an effective strategy for low-temperature heterogeneous integration. |
| Proceedings Inclusion? |
Planned: TMS Journal: Journal of Electronic Materials |
| Keywords |
Thin Films and Interfaces, Other, Other |