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Nuclear Reaction Probe of Oxygen Vacancy Migration in Electrically Fatigued PZT Thin Film Capacitors

Published online by Cambridge University Press:  15 February 2011

R.L. Pfeffer  and
W.D. Wilber
R.L. Pfeffer
Affiliation:
US Army Research Laboratory, Fort Monmouth, NJ 07703–5601
W.D. Wilber
Affiliation:
US Army Research Laboratory, Fort Monmouth, NJ 07703–5601
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Abstract

The migration of oxygen vacancies and their entrapment near film-electrode interfaces has been proposed as a cause of fatigue (i.e., polarization weakening) in ferroelectric thin film capacitors. To test this idea, lead zirconate titanate (PZT) thin films were epitaxially deposited by laser ablation on LaAlO3 substrates with yttrium barium cuprate (YBCO) base electrodes. Thin film capacitors were formed by deposition of noble metal (Pt) cap electrodes; half of them were then electrically fatigued by repeated polarization reversals (108 cycles). The distributions of oxygen in the two halves were then compared by means of accelerator-based nuclear backscattering (using the narrow elastic resonance at 3.045 MeV in the scattering of 4He from 16O) throughout the bulk of the PZT films and especially right under the Pt electrodes. We were unable to detect any difference in the oxygen profiles to within the accuracy of measurement, which was about 1 % of the oxygen concentration. Compositional changes, at least involving oxygen, do not seem to be responsible for the striking electrical alterations seen in fatigued PZT.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 361: Symposium I2 – Ferroelectric Thin Films IV , 1994 , 117
Copyright
Copyright © Materials Research Society 1995

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References

REFERENCES

1. Arit, G., Ferroelectrics 91, 3 (1989).Google Scholar
2. Arlt, G. and Robels, U., Integrated Ferroelectrics 3, 343 (1993).Google Scholar
3. Moazzami, R., Hu, C., and Shepherd, W.H., in IEEE Proceedings IEDM, 417 (1990).Google Scholar
4. Hu, H. and Krupanidhi, S.B., J. Appl. Phys. 74, 3373 (1993).Google Scholar
5. Pan, W., Sun, S., and Fuierer, P., J. Appl. Phys. 74, 1256 (1993).Google Scholar
6. Jiang, Q.Y., Subbarao, E.C., and Cross, L.E., J. Appl. Phys. 75, 7433 (1994).Google Scholar
7. Johnson, D.J., Amm, D.T., Griswold, E., Sreevinas, K., Yi, G., and Sayer, M. in Ferroelectric Thin Films I, edited by Myers, E.R., and Kingon, A.I. (Mat. Res. Soc. Proc. 200, Pittsburgh, PA, 1990) pp. 289–295.Google Scholar
8. Larsen, P.K., Dormans, G.J.M., Taylor, D.J., and van Veldhoven, P.J., J. Appl. Phys. 76, 2405 (1994).Google Scholar
9. Smyth, D.M., Ferroelectrics 116, 117 (1991).Google Scholar
10. Yoo, I.K. and Desu, S.B., Matls. Sci. Eng. B13, 319 (1992); Phys. Stat. Sol. (a) 133, 565 (1992); inGoogle Scholar
ISAF '92: Proceedings of the Eighth IEEE International Symposium on Applications of Ferroelectrics. edited by Liu, M., Safari, A., Kingon, A., and Haertling, G. (IEEE, 1992) pp. 225–228; inGoogle Scholar
Ferroelectric Thin Films III, edited by Myers, E.R., Tuttle, B.A., Desu, S.B., and Larsen, P.K. (Mat. Res. Soc. Proc. 310, Pittsburgh, PA, 1993) pp. 165–177.Google Scholar
11. Baiatu, T., Waser, R., Härdtl, K., J. Am. Ceram. Soc. 73, 1663 (1990).Google Scholar
12. Chen, J., Harmer, M.P., and Smyth, D.M., in ISAF '92: Proceedings of the Eighth IEEE International Symposium on Applications of Ferroelectrics, edited by Liu, M., Safari, A., Kingon, A., and Haertling, G. (IEEE, 1992) pp. 111–115. They observed donor doping to be more effective in BaTiO3 ceramics than in PZT films, where Pb vacancies from Pb loss during annealing combine with oxygen vacancies to form (VPb++-V0--) defect complexes, contributing to charge migration, and pyrochlore phase formation reduces donor incorporation into the perovskite structure.Google Scholar
13. Peng, J.-L. and Bursill, L.A., Ferroelectrics 70, 191 (1986).Google Scholar
14. Duiker, H.M., Beale, P.D., Scott, J.F., Paz de Araujo, C.A., Melnick, B.M., Cuchiaro, J.D., McMillan, L.D., J. Appl. Phys. 68, 5783 (1990).Google Scholar
15. Scott, J.F., Araujo, C.A., Melnick, B.M., McMillan, L.D., Zuleeg, R., J. Appl. Phys. 70, 382 (1991).Google Scholar
16. Cameron, J.R., Phys. Rev. 90, 839 (1953).Google Scholar
17. Blanpain, B., Revesz, P., Doolittle, L.R., Purser, K.H., and Mayer, J.W., Nucl. Instr. and Meth. Phys. Res. B34, 459 (1988).Google Scholar
18. Revesz, P., Li, J., Szabo, N. Jr, Mayer, J.W., Caudillo, D., and Myers, E.R. in Ferroelectric Thin Films II. edited by Kingon, A.I., Myers, E.R., and Tuttle, B. (Mat. Res. Soc. Proc. 243, Pittsburgh, PA, 1992) pp. 101–106.Google Scholar
19. The ion beam energy was calibrated just before this experiment by measuring an excitation curve for the 3.045 MeV resonance on a native oxide layer on polished beryllium.Google Scholar
20. Doolittle, L.R., Nucl. Instr. and Meth. B9, 344 (1985).Google Scholar
21. The thicknesses of the PZT and YBCO layers, expressed in units of å, were calculated from the fitted atomic areal densities assuming respective bulk atomic densities of 0.7(10)23 and 0.77(10)23 at/cm3.Google Scholar