Reliability of copper interconnects in integrated circuits

As dimensions shrink and current densities increase, the reliability of metal interconnects becomes a serious concern. In copper interconnects, the dominant diffusion path is along the interface between the copper and the top passivation layer (usually Si3N4). One of the predominant failure mechanisms in Cu has been open-circuit failure due to electromigration-induced void nucleation and growth near the cathode ends of interconnect segments. However, results from accelerated electromigration tests show that the simple failure analyses based on simple void nucleation and growth can not explain the wide range of times-to-failure that are observed, suggesting that other types of failure mechanisms are present. In this thesis, by devising and performing unique experiments through the development of an electromigration simulation tool, unexpected complex failure mechanisms have been identified that have significant effects on the reliability of copper interconnects. A simulation tool was developed by implementing the one-dimensional non-linear differential equation model first described by Korhonen et al. By applying an implicit method (Backward Euler method), the calculation time was significantly reduced, and stability increased, compared to previous tools based on explicit methods (Forward Euler method).

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Choi, Zung-Sun

Advisor dc:contributor.advisor

• Carl V. Thompson.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/39553
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/39553

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/39553