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Thermal Stability of High k Layers

Published online by Cambridge University Press:  11 February 2011

C. Zhao
Affiliation:
IMEC, Kapeldreef 75, B-3001, Leuven, Belgium
V. Cosnier
Affiliation:
International Sematech ST Microelectronics assignee in IMEC
P. J. Chen
Affiliation:
International Sematech Texas Instruments Inc. assignee in IMEC
O. Richard
Affiliation:
IMEC, Kapeldreef 75, B-3001, Leuven, Belgium
G. Roebben
Affiliation:
Department of Metallurgy & Material Engineering, K. U. Leuven, Leuven, Belgium
J. Maes
Affiliation:
ASM International NV, in IMEC
S. Van Elshocht
Affiliation:
IMEC, Kapeldreef 75, B-3001, Leuven, Belgium
H. Bender
Affiliation:
IMEC, Kapeldreef 75, B-3001, Leuven, Belgium
E Young
Affiliation:
International Sematech Philips assignee in IMEC
O. Van Der Biest
Affiliation:
Department of Metallurgy & Material Engineering, K. U. Leuven, Leuven, Belgium
M. Caymax
Affiliation:
IMEC, Kapeldreef 75, B-3001, Leuven, Belgium
W. Vandervorst
Affiliation:
IMEC, Kapeldreef 75, B-3001, Leuven, Belgium
S. De Gendt
Affiliation:
IMEC, Kapeldreef 75, B-3001, Leuven, Belgium
M. Heyns
Affiliation:
IMEC, Kapeldreef 75, B-3001, Leuven, Belgium
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Abstract

Thermal stability of amorphous phases in various high-k layers (Al2O3, ZrO2, HfO2, ZrAlOx, HfAlOx and HfSiOx) and the phase transformation of crystalline ZrO2 and HfO2 were studied experimentally, as functions of surface preparation, deposition conditions, material composition and post deposition thermal treatment. It is found that pure ZrO2 and HfO2 show relatively low crystallization onset temperatures. The crystalline ZrO2 or HfO2 phases are tetragonal or monoclinic, depending on the layer thickness. The phase transformation of metastable t-phase into stable m-phase has been observed in ZrO2 and HfO2. Crystallization behavior of Al2O3 depends on the surface preparation of the substrate. ALCVD grown Al2O3 layers on an oxide-based surface remain amorphous after 1100°C spike annealing, while those on HF-last surface crystallize at temperatures around 800°C. Alloying Al2O3 into ZrO2 and HfO2 can improve their resistance to crystallization under thermal exposure. The kinetics of the crystallization in the alloys can be described by linear TTT curves. Hf-aluminates show better thermal stability than Zr-aluminates. A defect model relative to the phase transformation is discussed, based on the above observations.

Type
Research Article
Copyright
Copyright © Materials Research Society 2003

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References

REFERENCES

1. Lucovsky, G., J. Vac. Sci. Technol. A 19, 1553 (2001)Google Scholar
2. Wilk, G. D., Wallace, R. M. and Anthony, J. M., App. Phys. Rev. 89, 5243 (2001)Google Scholar
3. Caymax, M. et. al. ALD2002 Conference, Hanyang University, Seoul, Korea Aug. 1921, 2000 Google Scholar
4. Afanas'ev, V. V., Stesmans, A. A., Mrstik, B. J., Zhao, C., Appl. Phys. Lett., 81, 1678 (2002).Google Scholar
5. Zhao, C., Roebben, G., Heyns, M. & Van der Biest, O., Key Engineering Materials 206–213, 1285 (2002)Google Scholar
6. Becher, P. F. and Swain, M. V., J. Am. Ceram. Soc. 75, 493 (1992).Google Scholar
7. Claussen, N., Wagner, R., Gaukler, L. J. & Petzow, G., J. Am. Ceram. Soc. 61, 369 (1978)Google Scholar
8. Delaey, L., Materials Science and Technology (Ben. Ed. Haasen, C. P., Kramer, E. J.), Vol. 5: Phase Transformation in Materials (Ed. By P. Haasen) (VCH, 1994) pp. 341402 Google Scholar
9. Chen, P. J., Lysaght, P. S., Bergmann, R., Messina, T., Sing, D. and Huff, H. R., 1st AVS Topical Conf. ALD, May 2001, Monterey, USA; J. Non-Crystal. Solids, 303, 54 (2002)Google Scholar
10. Kaushik, V.S. et. al. MRS 2002 Fall Meeting, Dec. 26, 2002 Boston, USA Google Scholar
11. Zhao, C. et. al. J. Non-Crys. Solid 303, 144 (2002).Google Scholar
12. Zhao, C. et. al. App. Phys. Lett. 80, 2374 (2002).Google Scholar