Cu contamination free hybrid bonding using MoS₂ passivation layer

다국어 초록 (Multilingual Abstract)

Hybrid bonding has become a crucial technology for three-dimensional (3D) semiconductor integration, offering simultaneous bonding of metal interconnects and dielectric layers. However, conventional hybrid bonding processes often suffer from contamination issues arising during O₂ plasma treatments, which are essential for generating hydroxyl groups on dielectric surfaces like SiCN. The energetic plasma environment induces Cu sputtering and metal migration, leading to both substrate and chamber contamination that degrade process stability over time. In this study, i suggest a contamination free approach using a molybdenum disulfide (MoS₂) barrier layer formed by plasma enhanced chemical vapor deposition (PECVD) sulfurization of a thin Mo film. The ultrathin MoS₂ film effectively prevents Cu sputtering during plasma treatment, eliminating contamination concerns while also allowing post bonding electrical conduction through controlled Cu filament formation based on memristive switching mechanisms. When a bias is applied across the Cu-MoS₂-Cu stack after hybrid bonding, Cu ions migrate through the MoS₂ and form conductive filaments, establishing reliable electrical connections without compromising bonding integrity. This method provides a comprehensive solution to Cu contamination in hybrid bonding and ensures excellent electrical performance, enabling high yield and contamination free processing for future 3D integrated semiconductor devices.

목차 (Table of Contents)

• Chapter 1. Introduction . 1
• 1.1 Research Background. 1
• 1.1.1 Limitations of Hybrid Bonding. 1
• 1.1.2 Characteristics of MoS2 among Transition Metal Dichalcogenides (TMDs). 4
• 1.1.3 Possibility of Solving the Problem of Handling MoS2 Passivation Layer. 5
• Chapter 2. TMD Material Synthesis and Samples with Hybrid Bonding. 6
• 2.1 PECVDAssisted Formation of Ultrathin MoS₂ Passivation Layers. 6
• 2.2 Hybrid Bonding enabled by MoS₂ Passivation. 13
• Chapter 3. Suppression of Cu Contamination and Improvement of Electrical Connectivity by MoS2. 18
• 3.1 Quantitative Evaluation of Cu Contamination Suppression. 18
• 3.2 MoS₂ Induced Cu Filament Formation for Post Bonding Electrical Connectivity. 21
• Chapter 4. Conclusion. 28
• References . 29
• 국문초록 . 36