Stacked film structured dependence of electromigration in Al-Cu interconnect terminated with W plug

Author

Matsumoto, S. ; Etoh, R. ; Ohtsuka, T. ; Kouzaki, T. ; Ogawa, S.

Author_Institution

Matsushita Electron. Corp., Kyoto, Japan

fYear

1998

fDate

1-3 Jun 1998

Firstpage

113

Lastpage

115

Abstract

We have investigated the stacked film structure dependence of the electromigration (EM) lifetime in AlCu interconnects terminated with W-plugs, the structures of which are Ti-TiN-AlCu-TiN, Ti-AlCu-TiN, and Ti-AlCu-Ti-TiN. It has been clarified that the dependence is caused by the difference in the time to deplete Cu atoms over a critical length. We found that the difference is caused by a reduction in the cross-section of the AlCu portion and the reduced Cu concentration in the AlCu portion which is induced by Al₃Ti formation. In addition, the difference is also caused by the increase in the interface between Al₃Ti and AlCu, which is the dominant Cu diffusion path

Keywords

aluminium alloys; chemical interdiffusion; copper alloys; diffusion barriers; electromigration; integrated circuit interconnections; integrated circuit metallisation; integrated circuit reliability; integrated circuit testing; interface structure; surface chemistry; tungsten; Al₃Ti formation; Al₃Ti-AlCu; Al₃Ti-AlCu interface; AlCu interconnects; AlCu portion cross-section; AlCu-W; Cu atom depletion; Cu concentration; Ti-AlCu-Ti-TiN; Ti-AlCu-Ti-TiN stack; Ti-AlCu-TiN; Ti-AlCu-TiN stack; Ti-TiN-AlCu-TiN; Ti-TiN-AlCu-TiN stack; W plug termination; critical length; dominant Cu diffusion path; electromigration; electromigration lifetime; stacked film structure dependence; Current density; Electromigration; Grain size; Optical films; Plasma temperature; Plugs; Probability distribution; Spectroscopy; Testing; Tin;

fLanguage

English

Publisher

ieee

Conference_Titel

Interconnect Technology Conference, 1998. Proceedings of the IEEE 1998 International

Conference_Location

San Francisco, CA

Print_ISBN

0-7803-4285-2

Type

conf

DOI

10.1109/IITC.1998.704766

Filename

704766