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Thermal stability, microstructure, and electrical properties of atomic layer deposited Hf6Ta2O17 gate dielectrics

Published online by Cambridge University Press:  31 January 2011

D.H. Triyoso ,
Z. Yu ,
R. Gregory ,
K. Moore ,
P. Fejes  and
S. Schauer
D.H. Triyoso*
Affiliation:
Austin Silicon Technology Solutions (ASTS), Freescale Semiconductor Inc., Austin, Texas 78721
Z. Yu
Affiliation:
Wireless and Packaging Systems Laboratory (WPSL), Freescale Semiconductor Inc., Phoenix, Arizona 85284
R. Gregory
Affiliation:
Wireless and Packaging Systems Laboratory (WPSL), Freescale Semiconductor Inc., Phoenix, Arizona 85284
K. Moore
Affiliation:
Wireless and Packaging Systems Laboratory (WPSL), Freescale Semiconductor Inc., Phoenix, Arizona 85284
P. Fejes
Affiliation:
Wireless and Packaging Systems Laboratory (WPSL), Freescale Semiconductor Inc., Phoenix, Arizona 85284
S. Schauer
Affiliation:
Wireless and Packaging Systems Laboratory (WPSL), Freescale Semiconductor Inc., Phoenix, Arizona 85284
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

The intent of this work is to investigate thermal stability, microstructure, and electrical properties of thin Hf6Ta2O17 high-k gate dielectrics. X-ray diffraction and transmission electron microscopy analysis reveal that an as-deposited Hf6Ta2O17 film is amorphous with a ∼1-nm interfacial layer. After a 1000 °C anneal, the film is a mixture of orthorhombic-Hf6Ta2O17 and monoclinic HfO2 with a thicker interfacial layer. Uniform Hf and Ta Auger depth profiles are observed for as deposited and annealed films. Secondary ion mass spectrometry (SIMS) analysis shows Hf and Ta profiles are unchanged following the 1000 °C anneal, indicating good thermal stability. There is, however, a clear indication of Si up-diffusion into Hf6Ta2O17, particularly after annealing at 1000 °C. No Hf or Ta is found in the Si substrate. Well-behaved capacitance-voltage curves and low leakage current characteristics were obtained for Mo/ Hf6Ta2O17 capacitors for as-deposited and 1000 °C annealed films. A flatband voltage (Vfb) shift towards negative voltage is observed for the annealed film when compared to the as-deposited film, indicating the presence of more positive charge, or less negative charge. Furthermore, capacitance-voltage stress measurements were performed to study charge trapping behaviors. A smaller Vfb shift is observed for as deposited (<10 mV) versus the 1000 °C annealed (30-40 mV) Hf6Ta2O17, indicating more charge trapping after the high temperature anneal.

Keywords

Atomic layer depositionDielectricMicrostructure
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 10 , October 2007 , pp. 2856 - 2862
Copyright
Copyright © Materials Research Society 2007

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References

REFERENCES

1Wilk, G.D., Wallace, R.M.Anthony, J.M.: High-kappa gate dielectrics: Current status and materials properties considerations. J. Appl. Phys. 89, 5243 2001CrossRefGoogle Scholar
2Triyoso, D.H., Hegde, R.I., Zollner, S., Ramon, M.E., Kalpat, S., Gregory, R., Wang, X-D., Jiang, J., Raymond, M., Rai, R., Werho, D., Roan, D., White, B.E. Jr.Tobin, P.J.: Impact of titanium addition on film characteristics of HfO2 gate dielectrics deposited by atomic layer deposition. J. Appl. Phys. 98, 54104-1 2005CrossRefGoogle Scholar
3Yu, X., Zhu, C., Wang, X.P., Li, M.F., Chin, A., Du, A.Y., Wang, W.D.Kwong, D-L.: High mobility and excellent electrical stability of MOSFETs using a novel HfTaO gate dielectric, Symposium on VLSI Technology. Digest of Technical Papers (IEEE Cat. No. 04CH37526 2004 110Google Scholar
4Zhang, M.H., Rhee, S.J., Kang, C.Y., Choi, C.H., Akbar, M.S., Krishnan, S.A., Lee, T., Ok, I.J., Zhu, F., Kim, H.S.Lee, J.C.: Improved electrical and material characteristics of HfTaO gate dielectrics with high crystallization temperature. Appl. Phys. Lett. 87, 232901-1 2005CrossRefGoogle Scholar
5Xiongfei, Y., Chunxiang, Z., Mingbin, Y.Kwong, D-L.: Improvements on surface carrier mobility and electrical stability of MOSFETs using HfTaO gate dielectric. IEEE Trans. Electron Devices 51(12), 2154 2004Google Scholar
6Lu, J.Kuo, Y.: Hafnium-doped tantalum oxide high-k dielectrics with sub-2 nm equivalent oxide thickness. Appl. Phys. Lett. 87, 232906 2005CrossRefGoogle Scholar
7Ritala, M.Leskela, M.: Atomic layer deposition in Handbook of Thin Films Materials edited by H. S. Nalwa Academic Press San Diego 2001 103Google Scholar
8Puurunen, R.: Surface chemistry of atomic layer deposition: A case study for the trimethylaluminum/water process. J. Appl. Phys. 97, 121301 2005CrossRefGoogle Scholar
9Zhao, C., Witters, T., Breimer, P., Maes, J., Caymax, M.De Gendt, S.: Properties of ALD HfTaxOy high-k layers deposited on chemical silicon oxide. Microelectron. Eng. 84, 7 2007CrossRefGoogle Scholar
10Kukli, K., Ihanus, J., Ritala, M.Leskela, M.: Tailoring the dielectric properties of HfO2–Ta2O5 nanolaminates. Appl. Phys. Lett. 68, 3737 1996CrossRefGoogle Scholar
11Kukli, K., Ihanus, J., Ritala, M.Leskela, M.: Properties of Ta2O5-based dielectric nanolaminates deposited by atomic layer epitaxy. J. Electrochem. Soc. 144, 300 1997CrossRefGoogle Scholar
12Triyoso, D., Liu, R., Roan, D., Ramon, M., Edwards, N.V., Gregory, R., Werho, D., Kulik, J., Tam, G., Irwin, E., Wang, X-D., La, L.B., Hobbs, C., Garcia, R., Baker, J., White, B.E. Jr.Tobin, P.: Impact of deposition and annealing temperature on material and electrical characteristics of ALD HfO2. J. Electrochem. Soc. 149, F155 2004Google Scholar
13Jiang, Z. X. Internal report (unpublished,2004Google Scholar
14Sivasubramani, P., Kim, J., Kim, M.J., Gnade, B.E.Wallace, R.M.: Effect of nitrogen incorporation on the thermal stability of sputter deposited lanthanum aluminate dielectrics on Si (100). Appl. Phys. Lett. 89, 152903 2006CrossRefGoogle Scholar
15Sivasubramani, P., Kim, J., Kim, M.J., Gnade, B.E., Wallace, R.M., Edge, L.F., Schlom, D.G., Craft, H.S.Maria, J-P.: Outdiffusion of La and Al from amorphous LaAlO3 in direct contact with Si (001). Appl. Phys. Lett. 86, 201901 2005CrossRefGoogle Scholar
16Sivasubramani, P., Lee, T.H., Kim, M.J., Kim, J., Gnade, B.E., Wallace, R.M., Edge, L.F., Schlom, D.G., Stevie, F.A., Garcia, R., Zhu, Z.Griffis, D.P.: Thermal stability of lanthanum scandate dielectrics on Si(100). Appl. Phys. Lett. 89, 242907 2006CrossRefGoogle Scholar
17Quevedo-Lopez, M.A., El-Bouanani, M., Gnade, B.E., Wallace, R.M., Visokay, M.R., Douglas, M., Bevan, M.J.Colombo, L.: Interdiffusion studies for HfSixOy and ZrSixOy on Si. J. Appl. Phys. 92, 3540 2002CrossRefGoogle Scholar
18Quevedo-Lopez, M.A., Visokay, M.R., Chambers, J.J., Bevan, M.J., LiFatou, A., Colombo, L., Kim, M.J., Gnade, B.E.Wallace, R.M.: Dopant penetration studies through Hf silicate. J. Appl. Phys. 97, 043508 2005CrossRefGoogle Scholar