Hostname: page-component-8448b6f56d-t5pn6 Total loading time: 0 Render date: 2024-04-24T15:44:31.062Z Has data issue: false hasContentIssue false

Stress in Silicon Due to the Formation of Self Aligned Poly-CoSi2 Lines Studied by Micro-Raman Spectroscopy

Published online by Cambridge University Press:  15 February 2011

D. J. Howard
Affiliation:
IMEC, Kapeldreef 75, B-3001 Leuven, Belgium.
I. De Wolf
Affiliation:
IMEC, Kapeldreef 75, B-3001 Leuven, Belgium.
H. Bender
Affiliation:
IMEC, Kapeldreef 75, B-3001 Leuven, Belgium.
K. Maex
Affiliation:
IMEC, Kapeldreef 75, B-3001 Leuven, Belgium.
Get access

Abstract

The application of CoSi2 in ever shrinking Si CMOS source-drain technologies demands a better knowledge of the states of stress caused by the formation of cobalt-silicides in Si. In this study the variation in local mechanical stress in the silicon substrate near arrays of polycrystalline cobalt-silicide lines was investigated by micro-Raman spectroscopy. The lines were formed by annealing Co sputtered in windows in lithographically patterned, thermal oxide coated Si wafers. The CoSi2 lines varied in width from ˜0.25 to 5.0μ, in number from 2 to 7, and in thickness from ˜ 10 to 230nm. The spacing between lines was 1 and 3 times the line width.

Trends in the Si stress between CoSi2 lines are described as a function of line width and line thickness. From the stress measured in the Si, information is obtained about the stress in the CoSi2 lines. In addition, the Si stress due to lines of primarily CoSi phase (monosilicide) is compared with the Si stress due to polycrystalline-CoSi2 (disilicide) lines.

Cross section TEM and SEM micrographs of the CoSix line morphologies are used to aid the description of the resulting stress profiles. Some theoretical modeling of the stress in the Si due to the CoSix lines is presented for comparison with the micro-Raman spectroscopy results.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

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. Maex, K., Mat. Sci. Eng., R 11, p. 53, 1993.Google Scholar
2. Van den Hove, L., Vanhellemont, J., Wolters, R., Claassen, W., De Keersmaecker, R., and Declerck, G., in Advanced Materials for ULSI, M. Scott ed., Proceedings of the First International Symposium on Advanced Materials for ULSI, Electrochem. Soc., 88–19, p. 165, 1988.Google Scholar
3. Ito, T., Azuma, H., and Noda, S., Jpn. J. Appl. Phys., 33 (10), p.5681, 1994.Google Scholar
4. Van den Hove, L., thesis: Advanced Interconnection and Contact Schemes Based on TiSi2 and CoSi2: Relevant Materials Issues and Technological Implementation, Katholieke Univ. Leuven, Belgium, June 1988.Google Scholar
5. De Wolf, I., Semi. Sci. & Tech., 10, p. 1, 1995.Google Scholar
6. Hu, S.M., Appl. Phys. Lett., 32 (1), p. 5, 1978.Google Scholar
7.. Murarka, S.P., Mat. Res. Soc. Symp. Proc. on Silicides. Germanides, and Their Interfaces, R.W., Fathauer ed., 320, p. 3, 1994.Google Scholar
8. Schreutelkamp, R.J., Coppye, W., De Bosscher, W., van Meirhaeghe, R., van Meirhaeghe, L., Vanhellemont, J., Deweerdt, B., Lauwers, A., and Maex, Karen, J. Mat. Res., 8 (12), p. 3111, 1993.Google Scholar
9. De Wolf, I., Maes, H.E., Moffet, J., and Ignat, M., to be published in Mat. Res. Soc. Symp. Proc. on Reliability in Microelectronics V, Spring Meeting, 1995.Google Scholar
10. De Wolf, I., Maes, H.E., and Jones, S.K., to be published in J. Appl. Phys., 1996.Google Scholar