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Gold Diffusion in Silicon During Gettering by an Aluminum Layer

Published online by Cambridge University Press:  10 February 2011

Subhash M. Joshi
Affiliation:
Duke University, Department of Mechanical Engineering and Materials Science, Durham, NC 27708
Ulrich M. Gösele
Affiliation:
Duke University, Department of Mechanical Engineering and Materials Science, Durham, NC 27708
Teh Y. Tan
Affiliation:
Duke University, Department of Mechanical Engineering and Materials Science, Durham, NC 27708
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Abstract

Previous modeling of Al gettering of Au in Si indicated that, for an Al gettering layer placed on one surface of a Si wafer, Au will be gettered from both surface regions of the wafer to progressively greater depths with time. This is because, in Si, Au is a substitutional-interstitial (Aus-Aui) species with its diffusion governed by the kick-out mechanism which is mediated by Si self-inter-stitials (I). During gettering by the Al-Si liquid at one wafer surface, Aus atoms change over to Au atoms to rapidly migrate out of Si into the liquid. The changeover process consumes I. At the two wafer surface regions, the consumed I will be quickly replenished, while in the wafer interior an I undersaturation develops which hinders the Aus-Aui changeover and hence the gettering process. Experimental evidences which confirm the predictions have been obtained. Au was indiffused into a FZ Si wafer at 950°C for 16 hr. After removing the Au source and etching, samples from the in-diffused wafer were annealed at 1000°C without or with an Al layer on one surface. For samples without Al, there is no change in the net Au content, while the U-shaped indiffused profile becomes flatter. For samples with an Al layer, both wafer surface region Au concentrations were significantly decreased in 30 min while the wafer interior Au concentrations decreased only after annealing for longer times. The model predictions, the experimental results, and the implications on Si self-diffusion parameters will be discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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References

REFERENCES

1. Tan, T. Y., Gardner, E. E. and Tice, W. K., Appl. Phys. Lett. 30, 175 (1977).Google Scholar
2. Semiconductor Silicon 1994. edited by Huff, H. R., Bergholz, W. and Sumino, K. (The Electrochem. Soc, Pennington, NJ, 1994).Google Scholar
3. Narayanan, S., Wenham, S. R. and Green, M. A., IEEE Trans. Electron Dev. ED-37, 382 (1990).Google Scholar
4. Rohatgi, A., Sana, P. and Salami, J., Proc, 11th European Photovoltaic Solar Energy Conference (Harwood Academic Publishers, Switzerland, 1992) pp. 159163.Google Scholar
5. Thompson, R. D. and Tu, K. N., Appl. Phys. Lett. 41, 440 (1982).Google Scholar
6. Apel, M., Hanke, I., Schindler, R. and Schröter, W., J. Appl. Phys. 76, 4432 (1994).Google Scholar
7. Bruton, T. M., Mitchell, A., Teale, L. and Knobloch, J., Proc. 10th European Photovoltaic Solar Energy Conference (Kluwer Academic Publishers, Netherlands, 1991) pp. 667669.Google Scholar
8. Hartiti, B., Slaoui, A., Muller, J. C. and Siffert, P., Appl. Phys. Lett. 63, 1249 (1993).Google Scholar
9. Joshi, S. M., Gösele, U. M. and Tan, T. Y., J. Appl. Phys. 77, 3858 (1995).Google Scholar
10. Stolwijk, N. A., Schuster, B. and Hölzl, J., Appl. Phys. A 33, 133 (1984).Google Scholar
11. Bronner, G. B. and Plummer, J. D., J. Appl. Phys. 61, 5286 (1987).Google Scholar
12. Ghaderi, K., Hobler, G., Budil, M., Mader, L. and Schulze, H. J., J. Appl. Phys. 77, 1320 (1995).Google Scholar
13. Gösele, U., Frank, W. and Seeger, A., Appl. Phys. 23, 361 (1980).Google Scholar
14. Stolwijk, N. A., Hölzl, J., Frank, W., Weber, E. R. and Mehrer, H., Appl. Phys. A 39, 37 (1986).Google Scholar
15. Bullis, W. M., Solid-State Electron., 9, 143 (1966).Google Scholar
16. Gafiteanu, R., Gösele, U. M. and Tan, T. Y., in Defect and Impurity Engineered Semiconductors and Devices, edited by Ashok, S., Chevallier, J., Akasaki, I., Johnson, N.M., and Sopori, B.L. (Mater. Res. Soc. Proc. 378, Pittsburgh, PA, 1995) p. 297.Google Scholar
17. Coffa, S., Calcagno, L., Campisano, S. U. and Ferla, G., J. Appl. Phys. 69, 1350 (1991).Google Scholar
18. Tan, T. Y., Gafiteanu, R. and Gösele, U. M., in Semiconductor Silicon 1994 - Seventh International Symposium on Silicon Materials Science and Technology, edited by Huff, H. R., Bergholz, W. and Sumino, K. (The Electrochem. Soc, Pennington, NJ, 1994), p. 920.Google Scholar