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Extended X-Ray Absorption Fine Structure Studies of Impurities in Semiconductors

Published online by Cambridge University Press:  26 February 2011

F. Sette ,
S. J. Pearton ,
J. M. Poate  and
J. E. Rowe
F. Sette
Affiliation:
AT & T Bell Laboratories, Murray Hill, NJ 07974
S. J. Pearton
Affiliation:
AT & T Bell Laboratories, Murray Hill, NJ 07974
J. M. Poate
Affiliation:
AT & T Bell Laboratories, Murray Hill, NJ 07974
J. E. Rowe
Affiliation:
AT & T Bell Laboratories, Murray Hill, NJ 07974
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Abstract

We discuss Extended X-ray Absorption Fine Structure (EXAFS) experiments on impurities in semiconductors. The local structure of the impurity site is determined for the first, second and third neighbor shells. These studies are carried out on absorption edges in the soft x-ray region using a novel fluorescence detection scheme which reveals improved detection sensitivity when compared with more standard electron Auger yield methods. The higher detection sensitivity allows structural studies at atomic densities as low as 1018 at/cm3 and this technique is used to study the local structure of P and S impurities in GaAs and of S in Alx Gal−x, As at concentrations of 1019–1020 at/cm3. The P atoms are substitutional on As sites, and a breathing relaxation of the P first shell Ga atoms is responsible for a P-Ga distance of 2.38Å, which is 0.07Å shorter than the As-Ga distance in GaAs(2.45Å). No detectable relaxation is observed in the P second and third atomic shells. In S-doped GaAs we find two different populations of S-Ga bonds with nearly equal intensity and both with S located on the As sub-lattice. These findings indicate two different configurations of substitutional S in GaAs. The coexistence of two similarly populated, charge compensating configurations is the first structural evidence which allows us to explain the observation that in n-doped GaAs the electrical activity of donors is lower than the atomic concentration. Finally, we present experimental results on S impurities in AlxGal−x, As (0.2<x<0.5). In this system, at the Al concentrations we studied, the S impurities are bound only to Al and not to Ga atoms. We report the formation of an extended complex which is discussed in connection with the structural identification of DX centers in these materials.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 104 , 1987 , 515
Copyright
Copyright © Materials Research Society 1988

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References

REFERENCES

1.Citrin, P. H., Eisenberger, P., and Hewitt, R. C., Phys. Rev. Lett. 41, 309 (1978).Google Scholar
2. For a review, see Stöhr, J., in Chemistry and Physics of Solid Surfaces V, edited by Vanselow, R. and Howe, R., Springer Series in Chemical Physics, Vol.35 (Springer, Berlin, 1984), p.231, and in X-ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS, and XANES, edited by R. Prins and D. Koningsberger (Wiley, New York, 1985).Google Scholar
3.Jaklevic, J., Kirby, J. A., Klein, M. P., Robertson, A. S., Brown, G. S., and Eisenberger, P., Solid State Commun. 28, 679 (1977); J. B. Hastings, in EXAFS Spectroscopy, Techniques, and Applications, edited by B. K. Teo and D. C. Joy (Plenum, New York, 1981), p.171.Google Scholar
4.Krause, M. O., J. Phys. Chem. Ref. Data 8, 307 (1979).Google Scholar
5.Brennan, S., Stöhr, J., and Jaeger, R., Phys. Rev. B 94, 4871 (1981).Google Scholar
6.Stöhr, J., Kollin, E. B., Fischer, D. A., Hastings, J. B., Zaera, F. and Sette, F., Phys. Rev. Lett. 255, 1468 (1985).Google Scholar
7.Fischer, D. A., Hastings, J. B., Zaera, F., Stöhr, J., and Sette, F., Nucl. Instrum. Methods A 246, 561 (1986).Google Scholar
8.Heald, S. M., Keller, E., and Stern, E. A., Phys. Lett. 103A, 155 (1984).Google Scholar
9. For a discussion of electron-yield detection techniques see Stöhr, J., Noguera, C., and Kendelewicz, T., Phys. Rev. B 30, 5571 (1984).Google Scholar
10.Mikkelsen, J. C. and Boyce, J. C., Phys. Rev. Lett., 49, 1412 (1982).Google Scholar
11.Scheffler, M., Proceedings of the 2nd Int'l. Conf. on Shallow Impurity Centers (Trieste, July 1986, ed. Baldereschi, Elsevier) to be published and private comm.Google Scholar
12. See for example: “New Developments in Semiconductor Physics,” edited by Beleznay, F., Ferenczi, G. and Giber, J. (Springer-Verlag, Berkin 1980) and “Ion Implantation and Beam Processing” edited by J. S. Williams, J. M. Poate (Academic Press, New York 1984).Google Scholar
13.Lang, D. V.“DX Centers in III–V Alloys” in “Deep Levels in Semiconductors,” edited by Pantelides, S., Gordon and Breach, N.Y. (1985).Google Scholar
14.Wolfe, C. M. and Stillman, G. E., AppI. Phy. Lett. 27, (1975) 564.Google Scholar
15.Citrin, P. H., Rowe, J. E., Eisenberger, P., Phys. Rev. Lett. 28, (1983) 2299.Google Scholar
16.Lee, P. A., Citrin, P. H., Eisenberger, P., Kincaid, B. M., Rev. Modern Physics 59 (1981), 769.Google Scholar
17.Mikkelsen, J. C. and Boyce, J. B., Phys. Rev. B 28, (1983) 7130. The same results are found for Germanium: E. A. Stern, B. A. Bunker and S. M. Heald, Phys. Rev. B 21, (1980) 5521.Google Scholar
18.Morgan, T. N., Phys. Rev. B 94, 2664 (1986).Google Scholar
19.Bhattacharya, R. S., Rai, A. K., Yeo, Y. K., Pronko, P., Park, Y. S., Nucl. Inst. and Meth. 209/210 637 (1983) and R. S. Bhattacharya, P. Pronko, S. C. Ling: Appl. Phys. Lett. 42, 880 (1983).Google Scholar
20.Mooney, P. M., these proceedings.Google Scholar
21.Mizuta, M., Tachikawa, M., Kukimoto, H., and Minomura, S., Jpn. J. Appl. Phys. 24, L143 (1985); M. Tachikawa, T. Fujisawa, H. Kukimoto, A. Shibata, G. Oomi, and S. Minomura, Jpn. J. Appl. Phys. 24, L893 (1985).Google Scholar