Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-24T16:25:39.130Z Has data issue: false hasContentIssue false
  • English
  • Français

Scaling of Statistical and Physical Electromigration Characteristics in Cu Interconnects

Published online by Cambridge University Press:  01 February 2011

Martin Gall ,
Meike Hauschildt ,
Patrick Justison ,
Koneru Ramakrishna ,
Richard Hernandez ,
Matthew Herrick ,
Lynne Michaelson  and
Hisao Kawasaki
Martin Gall
Affiliation:
[email protected], Freescale Semiconductor, Austin Silicon Technology Solutions, 3501 Ed Bluestein Boulevard, MD: K10, Austin, TX, 78721, United States, (512) 933 6766
Meike Hauschildt
Affiliation:
[email protected], Freescale Semiconductor, Austin Silicon Technology Solutions, 3501 Ed Bluestein Boulevard, MD: K10, Austin, TX, 78721, United States
Patrick Justison
Affiliation:
[email protected], Freescale Semiconductor, Austin Silicon Technology Solutions, 3501 Ed Bluestein Boulevard, MD: K10, Austin, TX, 78721, United States
Koneru Ramakrishna
Affiliation:
[email protected], Freescale Semiconductor, Austin Silicon Technology Solutions, 3501 Ed Bluestein Boulevard, MD: K10, Austin, TX, 78721, United States
Richard Hernandez
Affiliation:
[email protected], Freescale Semiconductor, Austin Silicon Technology Solutions, 3501 Ed Bluestein Boulevard, MD: K10, Austin, TX, 78721, United States
Matthew Herrick
Affiliation:
[email protected], Freescale Semiconductor, Austin Silicon Technology Solutions, 3501 Ed Bluestein Boulevard, MD: K10, Austin, TX, 78721, United States
Lynne Michaelson
Affiliation:
[email protected], Vishay Electro-Films, 111 Gilbane Street, Warwick, RI, 02886, United States
Hisao Kawasaki
Affiliation:
[email protected], Freescale Semiconductor, 870 Rue Jean Monnet, Crolles Cedex, N/A, 38926, France
Get access

Abstract

Even after the successful introduction of Cu-based metallization, the electromigration (EM) failure risk has remained one of the important reliability concerns for most advanced process technologies. Ever increasing operating current densities and the introduction of low-k materials in the backend process scheme are some of the issues that threaten reliable, long-term operation at elevated temperatures. The main factors requiring attention and careful control are the activation energy related to the dominating diffusion mechanism, the resulting median lifetimes, and the lognormal standard deviation of experimentally acquired failure time distributions. Whereas the origin of the EM activation energy and the behavior of median lifetimes with continuing device scaling are relatively well understood, detailed models explaining the origin and scaling behavior of the lognormal standard deviation are scarce. The statistical behavior of EM-induced void sizes and resulting lifetime distributions appear to be explainable by geometrical variations of the void shapes and the consideration of kinetic aspects of the EM process. Using these models, expected lifetime distributions for future technology nodes can be simulated from current, experimentally obtained void size and lifetime distributions. These simulations have to include geometrical factors of the EM test structures and actual, on-chip interconnects, as well as kinetic aspects of the mass transport process, such as differences in interface diffusivity between the lines. By extrapolating the expected lifetime distributions for future technology nodes from current EM data, it is possible to predict when insertion of new process schemes, such as Cu-alloys and/or metallic coating of the Cu/passivation interface is required.

Keywords

electromigrationCumicrostructure
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 914: Symposium F – Materials, Technology and Reliability of Low-k Dielectrics and Copper Interconnects , 2006 , 0914-F06-01
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Hu, C.-K., Rosenberg, R., Rathore, H.S., Nguyen, D.B., Agarwala, B., Proc. IEEE Int. Interconnect Technology Conf., 267–269, (1999).Google Scholar
2 Hau-Riege, C.S., Thompson, C.V., Appl. Phys. Lett. 78(22), 3451–3453, (2001).Google Scholar
3 Ogawa, E.T., Lee, K.-D., Blaschke, V.A., Ho, P.S., IEEE Transactions on Reliability, 51(4), 403–419, (2002).Google Scholar
4 Zschech, E., Geisler, H., Zienert, I., Prinz, H., Langer, E., Meyer, M.A., Schneider, G., Proc. Adv. Met. Conf., San Diego, 305–311, (2002).Google Scholar
5 Hauschildt, M., Gall, M., Thrasher, S., Justison, P., Michaelson, L., Hernandez, R., Kawasaki, H., Ho, P.S., AIP Conf. Proc. of Stress Induced Phenomena in Metallization 741, 112–123, (2004).Google Scholar
6 Hauschildt, M., Ph.D. Dissertation, The University of Texas at Austin, 2005.Google Scholar
7 He, J., Xu, G., Suo, Z., AIP Conf. Proc. of Stress Induced Phenomena in Metallization 741, 15–26, (2004).Google Scholar
8 Sommer, J., Muschik, T., Herzig, C., Gust, W., Acta mater. 44(1), 327–334, (1996).Google Scholar
9 Meyer, M.A., Herrmann, M., Langer, E., Zschech, E., Microelectronics Engineering, 64, 375, (2002).Google Scholar
10 Liniger, E., Gignac, L., Hu, C.-K., Kaldor, S., J. Appl. Phys. 92(4), 1803–1810, (2002).Google Scholar
11 Zschech, E., Meyer, M.A., Langer, E., Proc. of Mater. Research Soc. Symp., 812, 361–372, (2004).Google Scholar
12 Rosenberg, R., Edelstein, D.C., Hu, C.-K., Rodbell, K.P., Annu. Rev. Mater. Sci., 30, 229–262, (2000).Google Scholar
13 Gall, M. et al., AIP Conf. Proc. of Stress Induced Phenomena in Metallization 741, 73–84, (2004).Google Scholar
14 Gall, M. et al., Electrochem. Soc. Proc., Vol. 2001–2, 410–425, (2001).Google Scholar
15 Hu, C.-K. et al., Appl. Phys. Lett. 81(10), 1782–1784, (2002).Google Scholar
16 Hu, C.-K. et al., Proc. IEEE Int. Rel. Phys. Symp., 222–228, (2004).Google Scholar
17 Michaelson, L., Gall, M., Fejes, P., Hauschildt, M., Garcia, S., Kim, K., Mathew, V., Acosta, E., Jiang, Z.-X., to be published in Proc. Adv. Met. Conf., Kyoto (2005).Google Scholar