Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-19T22:39:52.915Z Has data issue: false hasContentIssue false

Long Range Hydrogen Motion, Evolution, and Bonding in a-Si:H and a-Ge:H

Published online by Cambridge University Press:  25 February 2011

R. Shinar
Affiliation:
Microelectronics Research Center, Iowa State University, Ames, IA 50011
X.-L. Wu
Affiliation:
Ames Laboratory - USDOE and Physics Department, Iowa State University, Ames, IA 50011
S. Mitra
Affiliation:
Ames Laboratory - USDOE and Physics Department, Iowa State University, Ames, IA 50011
J. Shinar
Affiliation:
Ames Laboratory - USDOE and Physics Department, Iowa State University, Ames, IA 50011
Get access

Abstract

The results of secondary ion mass spectrometry and IR studies of hydrogen diffusion in a-Si:H and a-Ge:H are reviewed and discussed. In a-Si:H, the diffusion is significantly slower at low total H content. The exponent α of the power-law time dependent diffusion constant D(t) = Doo(ωt)−α does not decrease with temperature as 1-T/To. D(tL), for constant diffusion length L, thus deviates from an Arrhenius behavior. The “apparent” activation energy Ea and prefactor Do derived from lnD(tL) vs 1/T yield a Meyer-Neldel relation Do = Aooexp(Ea/kToo) irrespective of L, H content, or microstructure. Aoo ≅ 3.3 × 10−14cm2/s and Too ≅ 730K for 2.5 × 10−5 ≤ Do ≤ 102cm2/s and 1.3 ≤ Ea ≤ 2.2eV. The preliminary results on a-Ge:H are similar, with Aoo ≅ 1.3 × 10−15cm2/s and Too = 530K. It is suspected that deviations from an exponential distribution of H site energies, structural relaxation, and deep H trapping sites related to microvoids may all contribute to the deviation of α from a 1-T/To behavior. Measurements following prolonged annealing suggest structural relaxation that affects H-site energies.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

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

Kakalios, J., Street, R. A., and Jackson, W. B., Phys. Rev. Lett. 59, 1037 (1987).Google Scholar
Jackson, W. B. and Kakalios, J., Phys. Rev. B 37, 1020 (1988).Google Scholar
3. Muller, G., Appl. Phys. A 45, 41 (1988).Google Scholar
4. Jackson, W. B., Phys. Rev. B 38, 3595 (1988).Google Scholar
5. Jackson, W. B., Phys. Rev. B 41, 1059 (1990).Google Scholar
6. Pantelides, S. T., Phys. Rev. Lett. 57, 2979 (1986);Google Scholar
58, 1344 (1987);Google Scholar
Phys. Rev. B 36, 3479 (1987).Google Scholar
7. Carlson, D. E. and Magee, C. W., Appl. Phys. Lett. 33, 81 (1978).Google Scholar
8. Crank, J., The Mathematics of Diffusion, (Clarendon, Oxford, England, (1975)), chap. 2.Google Scholar
9. Street, R. A., Tsai, C. C., Kakalios, J., and Jackson, W. B., Phil. Mag. B 56, 305 (1987).Google Scholar
10. Spear, W. E. and LeComber, P. G., in The Physics of HYdrogenated Amorphous Silicon I, edited by Joannopoulos, J. D. and Lucovsky, G., (Springer-Verlag, NY, 1984), Chap. 3.Google Scholar
11. Shinar, J., Shinar, R., Mitra, S., and Kim, J.-Y., Phys. Rev. Lett. 62, 2001 (1989).Google Scholar
12. Mitra, S., Wu, X.-L., Shinar, R., and Shinar, J., in Amorphous Silicon Technology - 1989, edited by Madan, A., Thompson, M. J., Taylor, P. C., Hamakawa, Y., and Lecomber, P. G. (Mat. Res. Soc. Proc. 149, Pittsburgh, PA, 1989) p. 595;Google Scholar
Shinar, R., Mitra, S., Wu, X.-L., and Shinar, J., J. Non-Cryst. Sol. 114, 220 (1989).Google Scholar
13. Cardona, M., Phys. Stat. Sol. (b) 118, 463 (1983).Google Scholar
14. Shanks, H. R. et al., J. Phys. (Paris) Colloq. 42 C4-773 (1981).Google Scholar
15. Albers, M. L., Shinar, J., and Shanks, H. R., J. Appl. Phys. 64, 1859 (1988).Google Scholar
16. Biswas, R., Kwon, I., Bouchard, A. M., Soukoulis, C. M., and Grest, G. S., Phys. Rev. B 39, 5101 (1989).Google Scholar
17. Smith, Z E. and Wagner, S., Phys. Rev. B 32, 5510 (1985);Google Scholar
Smith, Z E. et al., Phys. Rev. Lett. 57, 2450 (1986);Google Scholar
Shepard, K. et al., Appl. Phys. Lett. 53, 1644 (1988).Google Scholar
18. Kelires, P. C. and Tersoff, J., Phys. Rev. Lett. 61, 562 (1988).Google Scholar
19. Jackson, W. B., Tsai, C. C., and Thompson, R., Phys. Rev. Lett. 64, 56 (1990).Google Scholar
20. Roorda, S. et al., Phys. Rev. Lett. 62, 1880 (1990).Google Scholar
21. Fritzsche, H. and Deng, X.-M., Bull. Am. Phys. Soc. 35, 349 (1990).Google Scholar
22. Shinar, J., Shinar, R., Wu, X.-L., Mitra, S., and Girvan, R. F., to be publishedGoogle Scholar
23. Dyre, J. C., J. Phys. C 19, 5655 (1986).Google Scholar
24. Tang, X.-M. et al., to be published.Google Scholar