Hostname: page-component-848d4c4894-2xdlg Total loading time: 0 Render date: 2024-06-30T00:02:00.707Z Has data issue: false hasContentIssue false
  • English
  • Français

Density Reduction: A Mechanism For Amortization at High Ion Doses

Published online by Cambridge University Press:  15 February 2011

E. D. Specht ,
D. A. Walko  and
S. J. Zinkle
E. D. Specht
Affiliation:
Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831–6118
D. A. Walko
Affiliation:
Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831–6118
S. J. Zinkle
Affiliation:
Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831–6118
Get access

Abstract

At cryogenic temperatures, the accumulation of vacancy-interstitial pairs in Al2O3 from atomic displacements associated with ion implantation produces amorphization. At room temperature, these pairs recombine, and amorphization occurs only at high doses. X-ray reflectivity measurements show that amorphization of the surface of Al2O3 implanted at room temperature with 160 keV Cr+ ions is preceded by a progressive reduction in near-surface density. Monte Carlo simulations show that this density reduction can be accounted for by high-energy-transfer collisions which knock atoms deep into the target, leaving widely separated vacancies and interstitials, which do not recombine. Electron Microscopy shows that at least some of these vacancies condense into voids. We propose that this reduction in near-surface density can lead to amorphization at high doses. We present simple approximations for the density reduction expected for different ions and targets.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 321: Symposium E – Crystallization and Related Phenomena in Amorphous Materials—Ceramics, Metals, Polymers, and Semiconductors , 1993 , 399
Copyright
Copyright © Materials Research Society 1994

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

REFERENCES

1. Burnett, P.J. and Page, T.F., Radiat. Eff. 97, 283 (1986).Google Scholar
2. Glaser, E., Götz, G., Sobolev, N., and Wesch, W., Phys. Status Solidi A 69, 603 (1982).Google Scholar
3. White, C.W., McHargue, C.J., Sklad, P.S., Boatner, L.A., and Farlow, G.C., Mater. Sci. Rep. 4, 41 (1989).Google Scholar
4. Brimhall, J.L. and Simonen, E.P., Nucl. Instrum. and Meth. B 16, 187 (1986).Google Scholar
5. Burnett, P.J. and Page, T.F., J. Mater. Sci. 20, 4624 (1985).Google Scholar
6. O'Hern, M.E., McHargue, C.J., White, C.W., and Farlow, G.C., Nucl. Instrum. and Meth. B 46, 171 (1990).Google Scholar
7. Noda, S., Doi, H., and Kamigaito, O., J. Mater. Res. 4, 671 (1989).Google Scholar
8. Bull, S.J., J. Mater. Sci. 26, 3086 (1991).Google Scholar
9. McHargue, C.J., et al, Nucl. Instrum. and Meth. B 16, 212 (1986).Google Scholar
10. Specht, E.D., Walko, D.A., and Zinkle, S.J., Nucl. Instrum. and Meth. B (in press).Google Scholar
11. Parratt, L.G., Phys. Rev. 95, 359 (1954).Google Scholar
12. Hioki, T., Itoh, A., Ohkubo, M., Noda, S., Doi, H., Kawamoto, J., and Kaigaito, O., J. Mater. Sci. 21, 1321 (1986).Google Scholar
13. Specht, E.D., Sparks, C.J., and McHargue, C.J., Appl. Phys. Lett. 60, 2216 (1992).Google Scholar
14. See Biersack, J.P. and Haggmark, L.G., Nucl. Instrum. and Meth. 174, 257 (1980) for the original TRIM program. TRIM89 has been modified by Sjoreen, T.P. (unpublished) to include different displacement thresholds for elements in compound Materials.Google Scholar
15. Sigmund, P., Rev. Roum. Phys. 17, 823 (1972).Google Scholar
16. Oishi, Y. and Kingery, W.D., J. Chem. Phys. 33, 480 (1960).Google Scholar
17. Paladino, A.E. and Kingery, W.D., J. Chem. Phys. 37, 957 (1962).Google Scholar
18. Gulden, T.D., Philos. Mag. 15, 453 (1966).Google Scholar
19. Lee, W.E., Jenkins, M.L., and Pells, G.P., Phil. Mag. A 51, 639 (1985).Google Scholar