Hostname: page-component-848d4c4894-8kt4b Total loading time: 0 Render date: 2024-06-16T08:30:48.074Z Has data issue: false hasContentIssue false

The effects of capping barrier layers on the compositional and structural variations of integrated Pb(Zr, Ti)O3 ferroelectric capacitor having the dimension 3 × 3 μm2

Published online by Cambridge University Press:  31 January 2011

Cheol Seong Hwang*
Affiliation:
School of Materials Science and Engineering, Seoul National University, San #56-1, Shillim-Dong, Kwanak-Ku, Seoul, 151-742, Korea
Ju Cheol Shin
Affiliation:
School of Materials Science and Engineering, Seoul National University, San #56-1, Shillim-Dong, Kwanak-Ku, Seoul, 151-742, Korea
Jae Bin Lee
Affiliation:
School of Materials Science and Engineering, Seoul National University, San #56-1, Shillim-Dong, Kwanak-Ku, Seoul, 151-742, Korea
Jae-hoo Park
Affiliation:
School of Materials Science and Engineering, Seoul National University, San #56-1, Shillim-Dong, Kwanak-Ku, Seoul, 151-742, Korea
Young Jin Cho
Affiliation:
School of Materials Science and Engineering, Seoul National University, San #56-1, Shillim-Dong, Kwanak-Ku, Seoul, 151-742, Korea
Hyeong Joon Kim
Affiliation:
School of Materials Science and Engineering, Seoul National University, San #56-1, Shillim-Dong, Kwanak-Ku, Seoul, 151-742, Korea
Sang Yung Lee
Affiliation:
Semiconductor R&D Center, Samsung Electronics Company, San #24, Nongseo-Lee, Kiheung-Eup, Yongin-Si, Kyungki-Do, 463-060, Korea
Soon Oh Park
Affiliation:
Semiconductor R&D Center, Samsung Electronics Company, San #24, Nongseo-Lee, Kiheung-Eup, Yongin-Si, Kyungki-Do, 463-060, Korea
*
a)Address all correspondence to this author. e-mail: cheolsh@plaza.snu.ac.kr
Get access

Abstract

Structure and composition of the ferroelectric Pb(Zr, Ti)O3 layers in a capacitor of the ferroelectric random-access memory (FeRAM) device having a density of 64 k were investigated by transmission electron microscopy (TEM) together with the energy-dispersive spectroscopy (EDS) technique. The 250 nm thick PZT layer derived by the sol-gel route showed a 2–3% Pb-deficient, 3–4% Ti-deficient, and 5–7% Zr-excess composition at the top electrode interface compared to the bulk composition when they were as-fabricated. The local compositional nonuniformity became more critical as the integration process proceeded, which seriously degraded the ferroelectric hysteresis and the device yield. The major cause of the compositional variation was the outward diffusion of Pb through the capping barrier TiO2 layer during annealing at 650 °C. The AlN capping barrier layer was also not effective in suppressing the diffusion of Pb. However, the Al2O3/TiO2 double capping layer was very effective in suppressing the outward diffusion of Pb, and excellent ferroelectric characteristic was expected.

Type
Articles
Copyright
Copyright © Materials Research Society 1999

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.Chung, D.J., Lee, S. Y., Koo, B.J., Hwang, Y. S., Shin, D. W., Lee, J. W., Chun, Y. S., Shin, S. H., Lee, M.H., Park, H. B., Lee, S. I., Kim, K., and Lee, J. G., Symp. VLSI Tech. Digest of Tech. Papers (Honolulu, 1998), p. 122.Google Scholar
2.Tanabe, N., Kobayashi, S., Miwa, T., Amanuma, K., Mori, H., Inoue, N., Takeuchi, T., Saitoh, S., Saitoh, S., Hayashi, Y., Yamada, J., Koike, H., Hada, H., and Kunio, T., Symp. VLSI Tech. Digest of Tech. Papers (Honolulu, 1998), p. 124.Google Scholar
3.Kachi, T., Shoji, K., Yamashita, H., Kisu, T., Torii, K., Kumihashi, T., Fujisaki, Y., and Yokoyama, N., Symp. VLSI Tech. Digest of Tech. Papers (Honolulu, 1998), p. 126.Google Scholar
4.Chung, D.J., Kang, N.S., Lee, S. Y., Koo, B. J., Lee, J. W., Park, J. H., Chun, Y.S., Lee, M.H., Jeon, B. G., Lee, S.I., Shim, T. E., and Hwang, C.G., Symp. VLSI Tech. Digest of Tech. Papers (Kyoto, 1997), p. 139.Google Scholar
5.Boyer, L. L., Velasquez, N., and Evans, J. T. Jr, Jpn. J. Appl. Phys. 36, 5799 (1997).CrossRefGoogle Scholar
6.Hintermaier, F., Hendrix, B., Desrochers, D., Roeder, J., Dehm, C., Fritsch, E., Hönlein, W., Mazuré, C., Nagel, N., Thwaite, P., Symp. VLSI Tech. Digest of Tech. Papers (Honolulu, 1998), p. 56.Google Scholar
7.Yang, H-M., Luo, J-S., and Lin, W-T., J. Mater. Res. 12, 1145 (1997).CrossRefGoogle Scholar
8.Nakamura, T., Nakao, Y., Kamisawa, A., and Takasu, H., Jpn. J. Appl. Phys. 34, 5184 (1995).CrossRefGoogle Scholar
9.Sandashivan, S., Aggarwal, S., Song, T.K., Ramesh, R., Evans, J.T. Jr, Tuttle, B. A., Warren, W. L., and Dimos, D., J. Appl. Phys. 83, 2165 (1998).CrossRefGoogle Scholar
10.Lee, J., Choi, C.H., Park, B. H., Noh, T.W., and Lee, J.K., Appl. Phys. Lett. 72, 3380 (1998).CrossRefGoogle Scholar
11.Moulson, A.J. and Herbert, J. M., in Electroceramics (Chapman and Hall, London, 1990), p. 283.Google Scholar
12.Scott, J. F., Integ. Ferro. 9, 1 (1995).CrossRefGoogle Scholar
13.Hwang, C.S. and Kim, H. J., J. Am. Ceram. Soc. 78, 337 (1995).CrossRefGoogle Scholar
14.Park, I.S., Kim, Y.K., Lee, S.M., Chung, J. H., Kang, S.B., Yoo, C.Y., Lee, S. I., and Lee, M. Y., Proc. Inter. Electr. Device Meet. (1997), p. 617.Google Scholar