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Effects of Interfacial States on Asymmetric Polarization Switchings of Epitaxial Bi4Ti3012 Thin Films

Published online by Cambridge University Press:  15 February 2011

Bae-Ho Park
Affiliation:
Department of Physics, Seoul National University, Seoul 151–742, Korea
Sang-Jin Hyun
Affiliation:
Department of Physics, Seoul National University, Seoul 151–742, Korea
S. H. Mun
Affiliation:
Department of Physics, Seoul National University, Seoul 151–742, Korea
T. W. Noh
Affiliation:
Department of Physics, Seoul National University, Seoul 151–742, Korea
J. Lee
Affiliation:
Department of Materials Engineering, Sung Kyun Kwan University, Suwon 440–746, Korea
See-Hyung Lee
Affiliation:
LG Corporate Institute of Technology, Seocho-gu, Seoul 137–140, Korea
W. Jo
Affiliation:
LG Corporate Institute of Technology, Seocho-gu, Seoul 137–140, Korea
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Abstract

Epitaxial Bi4Ti3012 (BTO) films with Lao0.5Sr0.5Co03 (LSCO) or Pt bottom electrodes were grown on MgO(OOl) substrates by pulsed laser deposition. Surprisingly, a symmetric Pt/BTO/Pt capacitor showed a highly asymmetric polarization switching and an asymmetric Pt/BTO/LSCO capacitor revealed a nearly symmetric polarization switching. To understand these intriguing phenomena, Auger electron spectroscopy and x-ray photoemission spectroscopy depth-profiles were used. The evidences for interdiffusions at the bottom BTO/Pt interface were found. To get further understanding on the interfacial states, a capacitance-voltage (C-V) measurement was performed on the Pt/BTO/Pt capacitor. By fitting the C-V data with a back-to-back Schottky diode model, built-in voltages at the top and the bottom interfaces were determined to be 1.1 V and 3.2 V, respectively. From the obtained built-in voltages, an asymmetric band diagram for the Pt/BTO/Pt structure was suggested. Therefore, the imprint failure can be explained by existence of asymmetric interracial states.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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References

REFERENCES

1. Scott, J. F. and Arauzo, C. A., Science, 246, 1400 (1989).Google Scholar
2. Muller, R. S. and Kamins, T. I., Device Electronics for Integrated Circuits (Wiley, New York), p. 401. Google Scholar
3. Lee, J., Ramesh, R., Keramidas, V. G., Warren, W. L., Pike, G. E., and Evans, J. T. Jr, Appl. Phys. Lett. 66, 1337(1995).Google Scholar
4. Jo, W., Cho, H-J., Noh, T. W., Kim, B. I., Kim, D-Y., Khim, Z. G., and Kwun, S-I., Appl. phys. Lett., 63, 2198 (1993);Google Scholar
Jo, W., Yi, G-C., Noh, T. W., Ko, D-K., Cho, Y. S., and Kwun, S-I., Appl. phys. Lett., 61, 1516 (1992).Google Scholar
5. Park, B. H., Noh, T. W., Lee, J., Kim, C. Y., and Jo, W., in Proceedings of Eighth International Symposium on Integrated Ferroelectrics, Tempe, Arizona, 1996. (in press).Google Scholar
6. Gopel, W., Anderson, J. A., Frankel, D., Jaehnig, M., Phillips, K., Schafer, J. A., and Rocker, G., Surface Sci., 139, 333 (1984).Google Scholar
7. Cox, P. A., The Electronic Structure and Chemistry of Solids (Oxford University Press, 1977), p. 214. Google Scholar
8. Lee, J. J., Alluri, P., and Dey, S. K., Appl. phys. Lett., 65, 2027 (1994)Google Scholar