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Cracking and Delamination of Vapour-Deposited Tantalum Films

Published online by Cambridge University Press:  16 February 2011

R. M. Fisher
Affiliation:
Center for Advanced Materials, Materials and Chemical Sciences Div., Lawrence Berkeley Laboratory, 1 Cyclotron Rd., Berkeley CA 94720
J. Z. Duan
Affiliation:
Center for Advanced Materials, Materials and Chemical Sciences Div., Lawrence Berkeley Laboratory, 1 Cyclotron Rd., Berkeley CA 94720
J. B. Liu
Affiliation:
Center for Advanced Materials, Materials and Chemical Sciences Div., Lawrence Berkeley Laboratory, 1 Cyclotron Rd., Berkeley CA 94720
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Abstract

Tantalum films begin to crack and spall during vapour deposition on glass at a thickness of 180 nm. Islands and ribbons, 10 – 30 µm in size, delaminate by crack growth along the Ta/glass interface for several gIm after which the crack penetrates into the glass to a depth of 0.5–1 µm and complete spalling occurs. X-ray diffraction showed that about 50 % of the original bct, β-tantalum, phase had transformed to the bcc α-Ta phase. When Ta was deposited on glass that was first covered with 52 nm of copper, spalling was observed to begin at a thickness of 105 nm. In this case, the film first cracks and then peels along the Cu/glass interface and curls into scrolls indicating the presence of a small stress gradient. X-ray diffraction of the asdeposited film, and electron diffraction of ion-milled flakes, showed that Ta films deposited on Cu-coated glass almost completely transform to bcc α-Ta. The critical thickness for delamination along the Cu/glass interface is about 1/2 that for cracking in the glass substrate when an intermediate layer of Cu is not present. All of the above findings are in good agreement with previous observations on Cr films.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

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References

REFERENCES

[1] Fisher, R.M. and Duan, J.Z., in Proceedings of the lVth Asia-Pacific Conference on Electron Microscopy, (1988) p. 225.Google Scholar
[2] Fisher, R.M., Fox, A.G., Duan, J.Z., MRS Fall 1988 Meeting, Boston, MA (Mater. Res. Soc. Proc. 130, Pittsburgh PA 1989) p. 249.Google Scholar
[3] Robert Fisher, M. and Duan, J.Z., in, MRS Spring edited by DeKoven, B.M., Gillman, A.J. and Rosenberg, R. (Mater. Res. Soc. Symp. Proc. J53. Pittsburgh, PA 1989) p. 299.Google Scholar
[4] Duan, J. Z., Hetherington, C., Fisher, R.M., in Proceedings of 46th Annual Meeting of the Electron Microscooy Society of America (1988) p. 560.Google Scholar
[5] Fisher, R.M., Duan, J.Z., Hetherington, C., 9th European Congress on Electron Microscopy, York, England, (Inst. Phys. Conf. Ser. Vol.2, No. 93, 1988) p. 359.Google Scholar
[6] Hieber, K. and Mayer, N.M., Thin Solid Films 20 43 (1982).Google Scholar
[7] Fisher, R.M. and Duan, J.Z., in Evaluation of Adhesive Strength From Observations of Delamination Induced by Internal Stress, MRS Spring 1988 Meeting, Reno, Nevada, April 1988.Google Scholar
[8] Fisher, R.M., Duan, J.Z., Fox, A.G., Mater. Sci. and Eng. A117, 3 (1989).Google Scholar
[9] Fisher, R.M., Duan, J.Z., Fox, A.G., Pacific Coast Regional Meeting of TMS-AIME, Lake Tahoe, California, March 1988.Google Scholar