Abstract
Tungsten/silicon multilayers with tungsten layers of a thickness of 1–2 nm were prepared by means of electron beam deposition. Their structure and thermal stability under rapid thermal annealing were investigated by a combination of x-ray diffraction techniques and cross-sectional transmission electron microscopy. The crystallization behavior was found to depend on the interdiffusion and mixing at the tungsten/silicon interfaces during deposition as well as during annealing. The as-deposited tungsten/silicon multilayers were amorphous and remained stable after annealing at 250 °C/40 s. Interdiffusion and crystallization occurred after annealing all samples from 500 °C/40 s up to 1000 °C/20 s. By performing the same heat treatment in the tungsten/silicon multilayers, the formation of body-centered cubic W was observed with a layer thickness ratio δW/δsi = 1, whereas tetragonal WSi2 was detected in tungsten/silicon multilayers with a layer thickness ratio of δw/δsi ∼0.25. This dependence of the crystallization products on the layer thickness ratio δw/δsi originates from the different phenomena of interdiffusion and mixing at the tungsten/silicon interfaces. The possible formation of bcc tungsten as a first stage of crystallization of tungsten-silicon amorphous phase, rich in tungsten, is discussed.
Similar content being viewed by others
References
P. Chakraborty, Int. J. Mod. Phys. B5, 343 (1991).
E. Ziegler, Y. Lepetre, S. Joksch, V. Saile, S. Mourikis, P. J. Viccare, G. Rolland, and F. Laugier, Rev. Sci. Instrum. 60, 1999 (1989).
S. P. Murarka, Suicides for VLSI Application (Academic Press, New York, 1983).
S. Luby, E. Majkova, P. Lobotka, I. Vavra, M. Jergel, R. Senderak, and J. Grno, Physica C 197, 35 (1992).
E. Majkova, P. Lobotka, I. Vavra, S. Luby, M. Jergel, S. Benacka, R. Senderak, B. George, and M. Vaezzadeh, Appl. Surf. Sci. 65/66, 752 (1993).
Z. Jiang, X. Hiang, W. Liu, and Z. Wu, J. Appl. Phys. 65, 196 (1989).
V. Dupuis, M. F. Ravet, C. Tete, M. Piecuch, and B. Vidal, J. Appl. Phys. 68, 3384 (1990).
J.B Kortright, S. Joksch, and E. Ziegler, J. Appl. Phys. 69, 168 (1991).
J. M. Molarius, S. Franssila, G. Drozdy, and J. Saarilahti, Appl. Surf. Sci. 53, 383 (1991).
S. Enzo, A. Benedetti, G. Fagherazzi, and S. Polizzi, J. Appl. Cryst. 21, 536 (1988).
A. Guinier, X-ray Diffraction (Freeman, San Francisco, CA, 1963).
H. P. Klug and L. A. Alexander, X-ray Diffraction for Polycrystalline and Amorphous Materials (John Wiley, New York, 1974).
G. S. Cargill III, Solid State Physics, edited by F. Seitz (Academic Press, New York, 1975), Vol. 30.
L. Meyerheim, B. Lengeier, and H. E. Goebel, J. Appl. Phys. 68, 2694 (1990).
X.M. Jiang, D.C. Xian, and Z.Q. Wu, Appl. Phys. Lett. 57, 2549 (1990).
C. A. Lucas, T. D. Nguyen, and J. B. Kortright, Appl. Phys. Lett. 59, 2100 (1991).
C.J. Smithells, Metals Reference Book, 5th ed. (Butterworth, Washington, DC, 1976).
Glassy Metals I and II, edited by H-J. Giintherodt and H. Beck (Springer-Verlag, Berlin, 1981 and 1983).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Brunel, M., Enzo, S., Jergel, M. et al. Structural characterization and thermal stability of W/Si multilayers. Journal of Materials Research 8, 2600–2607 (1993). https://doi.org/10.1557/JMR.1993.2600
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1557/JMR.1993.2600