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Analytical modeling of reservoir effect on electromigration in Cu interconnects

Published online by Cambridge University Press:  03 March 2011

Zhenghao Gan ,
A.M. Gusak ,
W. Shao ,
Zhong Chen ,
S.G. Mhaisalkar ,
T. Zaporozhets  and
K.N. Tu
Zhenghao Gan*
Affiliation:
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798
A.M. Gusak
Affiliation:
Department of Theoretical Physics, Cherkasy National University, Cherkasy 18017, Ukraine
W. Shao
Affiliation:
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798
Zhong Chen
Affiliation:
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798
S.G. Mhaisalkar
Affiliation:
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798
T. Zaporozhets
Affiliation:
Department of Theoretical Physics, Cherkasy National University, Cherkasy 18017, Ukraine
K.N. Tu
Affiliation:
Department of Materials Science and Engineering, University of California–Los Angeles, Los Angeles, California 90095-1595
*
a) Address all correspondence to this author. e-mail: ezhgan@yahoo.com.sg
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Abstract

Electromigration (EM) in Cu dual-damascene interconnects with extensions (also described as overhangs or reservoirs) ranging from 0 to 120 nm in the upper metal (M2) was investigated by an analytical model considering the work of electron wind and surface/interface energy. It was found that there exists a critical extension length beyond which increasing extension lengths ceases to prolong electromigration lifetimes. The critical extension length is a function of void size and electrical field gradient. The analytical model agrees very well with existing experimental results. Some design guidelines for electromigration-resistant circuits could be generated by the model.

Keywords

CuDiffusionElectromigration
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 1 , January 2007 , pp. 152 - 156
Copyright
Copyright © Materials Research Society 2007

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