AVS 47th International Symposium
    Manufacturing Science and Technology Thursday Sessions
       Session MS-ThA

Paper MS-ThA4
Mechanical Properties of a Cu­Ta Interface by Molecular Dynamics

Thursday, October 5, 2000, 3:00 pm, Room 304

Session: Advanced Modeling for IC Manufacturing
Presenter: E. Ristolainen, Tampere University of Technology, Finland
Authors: P. Heino, Tampere University of Technology, Finland
E. Ristolainen, Tampere University of Technology, Finland
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During last few years, the electrical and mechanical properties of copper have received a lot of interest in the electronics community, mainly because of its low electrical resistance. Last year at AVS1999@footnote 1@ we discussed mechanical properties of nanoscale copper connection and concentrated on pure copper. In this work we study the microstructure and strength of the copper interface. To prevent diffusion of copper into silicon, a barrier is needed. Furthermore, the barrier-copper system should be immiscible. It seems that tantalum is used most often as a barrier metal, and it has the needed properties. Here we study the copper-tantalum interface by means of molecular dynamics method and embedded atom potential. In the model the cross term potential has been optimized to reproduce the experimental (small and positive) heat of alloy formation. The interface is formed by depositing Cu on different single crystal Ta surfaces. The microstructure and properties under shear of the resulting interface are analyzed. @FootnoteText@@footnote 1@P. Heino, P. Holloway and E. Ristolainen: Strength of Nanoscale Copper Under Shear, Accepted for publication, J. Vac. Sci. Tech. A (2000).