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Electrical properties of Pt/Bi3.25La0.75Ti3O12/Pt thin film capacitors tailored by cerium doping

Published online by Cambridge University Press:  01 April 2006

S.K. Singh  and
H. Ishiwara
S.K. Singh*
Affiliation:
Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
H. Ishiwara
Affiliation:
Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan
*
a) Address all correspondence to this author. e-mail: singh@neuro.pi.titech.ac.jp
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Abstract

Cerium-doped Bi3.25La0.75Ti3O12 (BLT) thin films were fabricated by depositing sol-gel solutions on Pt/Ti/SiO2/Si 〈100〉 substrates. The Ce-doping in BLT up to 6.7% of Ti atoms did not affect the single-phase bismuth-layered structure but small modification was observed in structural orientation, which influenced the microstructure and ferroelectric properties of BLT films. As we did not observe any structural distortion in x-ray diffraction data, it was suggested that doped Ce4+ was converted to Ce3+ during the annealing at 750 °C, and cerium ions might be substituted at Bi-site in BLT films. The small amount of Ce doping (1% of Ti atoms) enhanced the remanent polarization and reduced the coercive field by about 17% in BLT films, and these films showed fatigue-free response up to 1010 switching cycles at 300 kV/cm applied fields. Moderately Ce-doped films (1.7% of Ti atoms) also showed fatigue-free response up to 1010 switching cycles in 200 kV/cm applied field, but the polarization was found to increase with switching cycles when applied field was higher than 200 kV/cm. After Ce doping, the oxygen vacancy concentration may decrease in BLT films, and consequently, one can expect less domain pinning and higher fatigue resistance. Under the high cycling field, the high probability of field-assisted unpinning may be the main cause for the increased polarization.

Keywords

FatigueFerroelectricSolution deposition
Type
Articles
Information
Journal of Materials Research , Volume 21 , Issue 4 , April 2006 , pp. 988 - 994
Copyright
Copyright © Materials Research Society 2006

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References

REFERENCES

1.Scott, J.F., de Araujo, C.A. Paz: Ferroelectric memories. Science 246, 1400 (1989).CrossRefGoogle ScholarPubMed
2.de Araujo, C.A. Paz, Cuchiaro, J.D., McMillan, L.D., Scoot, M.C., Scott, J.F.: Fatigue-free ferroelectric capacitors with platinum electrodes. Nature 374, 627 (1995).CrossRefGoogle Scholar
3.Park, B.H., Kang, B.S., Bu, S.D., Noh, T.W., Lee, L., Joe, W.: Lanthanum-substituted bismuth titanate for use in non-volatile memories. Nature 401, 682 (1999).CrossRefGoogle Scholar
4.Watanabe, T., Kojima, T., Sakai, T., Funakubo, H., Osada, M., Noguchi, Y., Miyayama, M.: Large remanent polarization of Bi4Ti3O12-based thin films modified by the site engineering technique. J. Appl. Phys. 92, 1518 (2002).CrossRefGoogle Scholar
5.Uchida, H., Yoshikawa, H., Okada, I., Matsuda, H., Iijima, T., Watanabe, T., Funakubo, H.: Fabrication of M3+-substituted and M3+/V5+-cosubstituted bismuth titanate thin films [M= lanthanoid] by chemical solution deposition technique. Jpn. J. Appl. Phys. 41, 6820 (2002).CrossRefGoogle Scholar
6.Chon, U., Jang, H.M., Kim, M.G., Chang, C.H.: Layered perovskites with giant spontaneous polarizations for nonvolatile memories. Phys. Rev. Lett. 89, 087601 (2002).CrossRefGoogle ScholarPubMed
7.Matsuda, H., Ito, S., Iijima, T.: Design and ferroelectric properties of polar-axis-oriented polycrystalline Bi4−xPrxTi3O12 thick films on Ir/Si substrates. Appl. Phys. Lett. 83, 5023 (2003).CrossRefGoogle Scholar
8.Noguchi, Y., Miyayama, M.: Large remanent polarization of vanadium-doped Bi4Ti3O12. Appl. Phys. Lett. 78, 1903 (2001).CrossRefGoogle Scholar
9.Wang, X., Ishiwara, H.: Polarization enhancement and coercive field reduction in W- and Mo-doped Bi3.35La0.75Ti3O12 thin films. Appl. Phys. Lett. 82, 2479 (2003).CrossRefGoogle Scholar
10.Duiker, H.M., Beale, P.D., Scott, J.F., de Araujo, C.A. Paz, Meinick, B.M., Cuchiaro, J.D.: Fatigue and switching in ferroelectric memories: theory and experiment. J. Appl. Phys. 68, 5783 (1990).CrossRefGoogle Scholar
11.Zhang, S.T., Chen, Y.F., Wang, J., Cheng, G.X., Liu, Z.G., Ming, N.B.: Ferroelectric properties of La and Zr substituted Bi4Ti3O12 thin films. Appl. Phys. Lett. 84, 3660 (2004).CrossRefGoogle Scholar
12.Joshi, P.C., Krupanidhi, S.B.: Structural and electrical studies on rapid thermally processed ferroelectric Bi4Ti3O12 thin films by metallo-organic solution deposition. J. Appl. Phys. 72, 5827 (1992).CrossRefGoogle Scholar
13.Park, B.H., Hyun, S.J., Bu, S.D., Noh, T.W., Lee, L., Kim, H-D., Kim, T.H., Joe, W.: Defferences in nature of defects between SrBi2Ta2O9 and Bi4Ti3O12. Appl. Phys. Lett. 74, 1907 (1999).CrossRefGoogle Scholar
14.Al-Shareef, H.N., Dimos, D., Boyle, T.J., Warren, W.L., Tuttle, B.A.: Qualitative model for the fatigue-free behavior of SrBi2Ta2O9. Appl. Phys. Lett. 68, 690 (1996).CrossRefGoogle Scholar
15.Wu, D., Li, A., Ling, H., Yu, T., Liu, Z., Ming, N.: Fatigue study of metalorganic-decomposition-derived SrBi2Ta2O9 thin films: The effect of partial switching. Appl. Phys. Lett. 76, 2208 (2000).CrossRefGoogle Scholar
16.Chu, M-W., Ganne, M., Caldes, M.T., Brohan, L.: X-ray photoelectron spectroscopy and high resolution electron microscopy studies of Aurivillius compounds: Bi4−xLaxTi3O12 (x = 0, 0.5, 0.75, 1.0, 1.5, and 2.0). J. Appl. Phys. 91, 3178 (2002).CrossRefGoogle Scholar
17.Crucq, A.: Catalysis and Automotive Pollution Control II (Elsevier, Amsterdam, The Netherlands, 1991).Google Scholar
18.Mamontov, E., Egami, T., Brezny, R., Koranne, M., Tyagi, S.: Lattice defects and oxygen storage capacity on nanocrystalline ceria and ceria-zirconia. J. Phys. Chem. B 104, 11110 (2000).CrossRefGoogle Scholar
19.Oh, Y.N., Yoon, S.G.: Structural and ferroelectric properties of (Bi,Ce)4Ti3O12 thin films grown by pulsed laser deposition for ferroelectric random access memories. Appl. Surf. Sci. 227, 187 (2004).CrossRefGoogle Scholar
20.Ryu, S.O., Lee, W.J., Lee, N.Y., Shin, W.C., You, I.K., Cho, S.M., Yoon, S.M., Yu, B.G., Koo, J.K., Kim, J.D.: Crystallographic orientations and electrical properties of Bi3.47La0.85Ti3O12 thin films on Pt/Ti/SiO2/Si and Pt/SiO2/Si substrates. Jpn. J. Appl. Phys. 42, 1665 (2003).CrossRefGoogle Scholar
21.Mandal, P., Hassen, A., Loidl, A.: Effect of Ce doping on structural, magnetic, and transport properties of SrMnO3 perovskite. Phys. Rev. B 69, 224418 (2004).CrossRefGoogle Scholar
22.Xiao, W., Guo, Q., Wang, E.G.: Transformation of CeO2(111) to Ce2O30001 films. Chem. Phys. Lett. 368, 527 (2003).CrossRefGoogle Scholar
23.Watanabe, T., Funakubo, H., Saito, K.: Ferroelectric property of epitaxial films prepared by metalorganic chemical vapor deposition. J. Mater. Res. 16, 303 (2001).CrossRefGoogle Scholar
24.Okamura, S., Takaoka, M., Nishida, T., Shiosaki, T.: Increase in switching charge of ferroelectric SrBi2Ta2O9 thin films with polarization reversal. Jpn. J. Appl. Phys. 39, 5481 (2000).CrossRefGoogle Scholar