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Highly textured nanostructure of pulsed laser deposited IrO2 thin films as investigated by transmission electron microscopy

Published online by Cambridge University Press:  31 January 2011

A. M. Serventi
Affiliation:
INRS-É nergie et Matériaux, 1650 Blvd. Lionel-Boulet, C.P. 1020, Varennes, Québec J3X 1S2, Canada
M. A. El Khakani*
Affiliation:
INRS-É nergie et Matériaux, 1650 Blvd. Lionel-Boulet, C.P. 1020, Varennes, Québec J3X 1S2, Canada
R. G. Saint-Jacques
Affiliation:
INRS-É nergie et Matériaux, 1650 Blvd. Lionel-Boulet, C.P. 1020, Varennes, Québec J3X 1S2, Canada
D. G. Rickerby
Affiliation:
European Community-Joint Research Centre, IHCP, 21020 Ispra (Va), Italy
*
a)Address all correspondence to this author.[email protected]
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Abstract

Highly conductive iridium dioxide (IrO2) thin films have been deposited onto in situ oxidized Si(100) substrates by means of a reactive pulsed laser deposition (PLD) process. The polycrystalline IrO2 films were obtained by ablating a metal iridium target under an optimal oxygen background pressure of 200 mtorr and at different substrate deposition temperatures (Td ) ranging from 350 to 550 °C. Conventional and high-resolution transmission electron microscopy (HRTEM) techniques were used to investigate the micro- and nanostructural changes of the PLD IrO2 films as a function of their deposition temperatures. The microstructure and the morphology of the PLD IrO2 films was found to change drastically from an irregular and loosely packed columnar structure at Td = 300 °C to a uniform and densely packed columnar structure for higher Td (≥350 °C). For IrO2 films deposited in the 350 ≤ Td ≤ 550 °C range, HRTEM have revealed the presence of highly textured arrangements of almost spherical IrO2 nanograins (of 3–5 nm diameter, regardless of Td) in the columns (of which diameter was found to increase from 85 ± 15 to 180 ± 20 nm as Td increases from 350 to 550 °C). Lattice resolution and dark-field imaging have pointed out the presence of large IrO2 crystallites made of many similarly oriented nanograins (i.e., under the same Bragg diffraction conditions). Moreover, a high continuity of the lattice planes across the entire crystallite was clearly observed. This latter aspect together with the highly textured nanostructure of the IrO2 films correlate well with their high conductivity (42 ± 6 μω cm for Td ≥ 400), which was found to be comparable with that of bulk single-crystal IrO2.

Type
Articles
Copyright
Copyright © Materials Research Society 2001

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References

REFERENCES

1Goodenough, J.B., Metallic Oxides-Progress in Solid State Chemistry, 5th ed., edited by Reiss, H. (Pergamon Press, London, United Kingdom, 1971).Google Scholar
2Nakamura, T., Nakao, Y., Kamisawa, A., and Takasu, H., Appl. Phys. Lett. 65, 152 (1994).Google Scholar
3Chuo, H.J., Kang, C.S., Hwang, C.S., Kim, J.W., Hori, H., Lee, B.T., Lee, S.I., and Lee, M.Y., Jpn. J. Appl. Phys. 36, L874 (1997).Google Scholar
4Cogan, S.F., Plante, T.D., McFaded, R.S., and Rauh, R.D., Sol. Energy Mater. 16, 371 (1987).Google Scholar
5Yamanaka, K., Jpn. J. Appl. Phys. 28, 632 (1989).Google Scholar
6Katsube, T., Lauks, I., and Zemel, J.N., Sens. Actuators 2, 399 (1982).Google Scholar
7Pasztor, K., Sekiguchi, A., Shimo, N., Kitamura, N., and Mashuara, H., Sens. Actuators B 12, 440 (1993).Google Scholar
8Kotz, R., Neff, H., and Stucki, S., J. Electrochem. Soc. 131, 72 (1984).Google Scholar
9Osaka, A., Takatsuna, T., and Miura, Y., J. Non-Cryst. Solids 178, 313 (1994).Google Scholar
10Briss, V., Myers, R., Angerstein-Kozlowska, H., and Conway, B.E., J. Electrochem. Soc. 131, 1502 (1984).Google Scholar
11Lezna, R.O., Kunimatsu, K., Ohtsuka, T., and Sato, N., J. Electrochem. Soc. 134, 3090 (1987).Google Scholar
12Aurian-Blajeni, B., Boucher, M.M., Kimbal, A.G., and Robblee, L.S., J. Mater. Res. 4, 440 (1989).Google Scholar
13Klein, J.D., Clauson, S.L., and Cogan, S.F., J. Mater. Res. 10, 328 (1995).CrossRefGoogle Scholar
14Liao, P.C., Ho, W.S., Huang, Y.S., and Tiong, K.K., J. Mater. Res. 13, 1318 (1998).Google Scholar
15El Khakani, M.A., Chaker, M., and Gat, E., Appl. Phys. Lett. 69, 2027 (1996).Google Scholar
16El Khakani, M.A. and Chaker, M., Thin Solid Films, 335, 6 (1998).Google Scholar
17El Khakani, M.A., Le Drogoff, B., and Chaker, M., J. Mater. Res. 14, 3241 (1999).Google Scholar
18El Khakani, M.A., Dolbec, R., Serventi, A.M., Horrillo, M.C., Trudeau, M., St-Jacques, R.G., Rickerby, D.G., and Sayago, I., Sens. Actuators B 77, 383 (2001).Google Scholar
19Alani, R., Jones, J., and Swann, P.R., in Specimen Preparation for Transmission Electron Microscopy of Materials II, edited by Anderson, R. (Mater. Res. Soc. Symp. Proc. 199, Pittsburgh, PA, 1990), p. 85.Google Scholar
20Malis, T.F. and Steele, D., in Specimen Preparation for Transmission Electron Microscopy of Materials II, edited by Anderson, R. (Mater. Res. Soc. Symp. Proc. 199, Pittsburgh, PA 1990), p. 3.Google Scholar
21Murakami, Y., Tsuchiya, S., Yahikozawa, K., and Takasu, Y., J. Mater. Sci. Lett. 13, 1773 (1994).CrossRefGoogle Scholar
22Vetrone, J., Foster, C.M., Bai, G-R., Wang, A., Patel, J., and Wu, X., J. Mater. Res. 13, 2281 (1998).Google Scholar
23Rickerby, D.G., Philos. Mag. B 76(4), 573 (1997).Google Scholar
24Chang, W., Cosandey, F., and Hahn, H., Nanostruct. Mater. 2, 29 (1993).Google Scholar
25Ryden, W.D., Lawson, A.W., and Saratain, C.C., Phys. Rev. B 1, 1494 (1970).Google Scholar