Hostname: page-component-848d4c4894-wzw2p Total loading time: 0 Render date: 2024-05-01T13:34:56.402Z Has data issue: false hasContentIssue false

The role of ion-beam cleaning in the growth of strained-layer epitaxial thin transition metal films

Published online by Cambridge University Press:  31 January 2011

Sung I. Park
Affiliation:
Stanford University, Stanford, California 94305
A. Marshall
Affiliation:
Stanford University, Stanford, California 94305
R. H. Hammond
Affiliation:
Stanford University, Stanford, California 94305
T. H. Geballe
Affiliation:
Stanford University, Stanford, California 94305
J. Talvacchio
Affiliation:
Westinghouse Research and Developement Center, Pittsburgh, Pennsylvania 15235
Get access

Abstract

Low-energy ion-beam cleaning of the substrates prior to a deposition greatly enhances the quality of ultrathin (< 100 Å) refractory superconducting (Nb, V) films. Using this technique Nb films as thin as 7 Å have been grown, from which good tunnel junctions have been fabricated. Both the native films and the tunnel junctions are sturdy and can be thermally recycled without any degradation. In-situ surface study along with transmission electron microscopy (TEM) results suggest the removal of the carbon atoms from the surface of the substrate without an apparent surface damage as the causes of the improvement. The TEM results indicate that the Nb films grow perfectly lattice matched to the sapphire substrate when the substrate is ion-beam cleaned. This strained-layer epitaxy is observed up to 40 Å, the maximum thickness investigated through TEM.

Type
Articles
Copyright
Copyright © Materials Research Society 1987

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Kodama, J., Itoh, M., and Hirai, H., J. Appl. Phys. 54, 4050 (1983).CrossRefGoogle Scholar
2Mayada, A. F., Laibowitz, R. B., and Cuomo, J. J., J. Appl. Phys. 43, 1287 (1972).CrossRefGoogle Scholar
3Quateman, J. H., Phys. Rev. B 34, 1948 (1986).CrossRefGoogle Scholar
4Wolf, S. A., Kennedy, J. J., and Nisenoff, M., J. Vac. Sci. Technol. 13, 145 (1976).CrossRefGoogle Scholar
5Hammond, R. H., IEEE Trans. Magn. MAG- 11, 210 (1975); R. H. Hammond J. Vac. Sci. Technol. 15, 382 (1978).CrossRefGoogle Scholar
6Pauw, L. J. Van der, Phillips Res. Rep. 13, 1 (1958).Google Scholar
7Park, S. I., PhD. thesis, Stanford University, 1986.Google Scholar
8Talvacchio, J., Janocko, M. A., Gavaler, J. R., and Braginski, A. I., Advances in Cryogenic Engineering-materials, edited by Clark, A. F. and Reed, R. P. (Plenum, New York, 1986), p. 527.CrossRefGoogle Scholar
9For example, see Carter, G., Navinsek, B., and Whitton, J. L., in Sputtering by Particle Bombardment, edited by Behrisch, R. (Springer, Berlin, 1981), Vol. 1; R. S. Nelson and D. J. Mazey, Rad. Effects 18, 127(1973).Google Scholar
10Broussard, P. (private communication).Google Scholar
11Bean, J. C., Feldman, L. C., Fiory, A. T., Nakahara, S., and Robinson, I. K., J. Vac. Sci. Technol. A 2, 436 (1984) and references therein.CrossRefGoogle Scholar
12Bean, J. C., Becker, G. E., Petroff, P. M., and Seidel, T. E., J. Appl. Phys. 48, 907 (1977).CrossRefGoogle Scholar