Cu-Contamination-Free Hybrid Bonding via MoS₂ Passivation Layer

Area of Science:

• Materials Science
• Semiconductor Manufacturing
• Nanotechnology

Background:

• Hybrid bonding is crucial for 3D semiconductor integration, enabling simultaneous metal and dielectric bonding.
• Conventional hybrid bonding faces contamination issues from O2 plasma treatment, causing copper sputtering and degrading reliability.
• Existing methods struggle with chamber and substrate contamination, impacting process yield.

Purpose of the Study:

• To develop a novel contamination-free hybrid bonding process.
• To address copper sputtering and metal migration during plasma treatment.
• To enable reliable post-bonding electrical connectivity.

Main Methods:

• Formation of an ultrathin molybdenum disulfide (MoS2) barrier layer via plasma-enhanced chemical vapor deposition (PECVD) sulfurization of Mo films.
• Utilizing the MoS2 layer to prevent copper sputtering during O2 plasma processing.
• Implementing memristive switching mechanisms for controlled copper filament formation post-bonding.

Main Results:

• The MoS2 barrier effectively prevented copper sputtering and eliminated chamber contamination.
• Post-bonding electrical connectivity was achieved through memristive switching of copper ions through the MoS2 layer.
• The hybrid bonding interface integrity and electrical performance were maintained.

Conclusions:

• The MoS2 barrier layer successfully resolves contamination issues in hybrid bonding.
• This approach offers a pathway to contamination-free, high-yield hybrid bonding for advanced 3D integration.
• The technology ensures reliable electrical performance for next-generation semiconductor devices.