Advertisement

Liquid Nitrogen Temperature DC SQUID’s Using Single-Target-Sputtered Films

  • W. J. Gallagher
  • R. H. Koch
  • R. L. Sandstrom
  • R. B. Laibowitz
  • A. W. Kleinsasser
  • B. Bumble
  • M. F. Chisholm
Conference paper

Abstract

For the reliable fabrication of thin-film devices with high temperature superconductors, we have developed a simple, single-target rf-magnetron sputtering process involving an unconventional sputtering geometry. The process allows reproducible formation of high transition temperature YBa2Cu3O7-x films from nearly stoichiometric targets and lends itself both to film growth with high temperature post anneals and to low temperature in situ film growth. The post-anneal process has been optimized to routinely yield epitaxial films on lattice matched substrates that are fully superconducting at 86~91 K with current densities at 77 K up to 8x105 A/cm2. Single-level dc SQUID’s have been made by patterning loops in lower current density films with conventional photolithography and ion milling. Noise measurements at 77 K indicate a flux noise level of 3 × 10-4Φo/√Hz at 20 Hz, dominated by low frequency (l/f) noise. The origin of the SQUID noise is elucidated by studying current-biased thin film stripes, which also show low-frequency noise. Both the current-voltage characteristics and the noise voltage spectrum of the stripes are consistent with expectations from flux-flow but not from Josephson coupling between grains. Further improvements in SQUID noise performance will probably require the use of higher current density films with localized Josephson regions.

Keywords

Critical Current Density Dynamic Resistance Flux Flow Flux Noise Stoichiometric Target 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    R.B. Laibowitz, R.H. Koch, P. Chaudhari, and R.J. Gambino, Phys. Rev. B35, 8821 (1987)ADSGoogle Scholar
  2. 1a.
    P. Chauclhari, R.H. Koch, R.B. Laibowitz, T.R. McGuire and R. J. Gambino, Phys. Rev. Lett. 58, 2684 (1987).ADSCrossRefGoogle Scholar
  3. 2.
    B. Oh, M. Naito, S. Arnason, P. Rosenthal, R. Barton, M. R. Beasley, T. H. Geballe, R. H. Hammond and A. Kapitulnik, Appl. Phys. Lett. 51, 852 (1987)ADSCrossRefGoogle Scholar
  4. 2a.
    M. Naito, R.H. Hammond, B. Oh, M.R. Hahn, J.W.P. Hsu, P. Rosenthal, A.F. Marshall, M.R. Beasley, T.H. Geballe, and A. Kapitulnik, J. Mat. Res. 2, 713 (1987).ADSCrossRefGoogle Scholar
  5. 3.
    R.M. Silver, J. Talvacchio, and A.L. de Lozanne, Appl. Phys. Lett., 51, 2149 (1987).ADSCrossRefGoogle Scholar
  6. 4.
    M.R. Scheuermann, C.C. Chi, C.C. Tsuei, D.S. Yee, J.J. Cuomo, R.B. Laibowitz, R.H. Koch, B. Braren, R. Srinivasen, and M.M. Plcchaty, Appl. Phys. Lett., 51, 1951 (1987).ADSCrossRefGoogle Scholar
  7. 5.
    D. Dijikkamp, T. Venkatesan, X. D. WU, S. A. Shaheen, N. Jisrawi, Y. H. Min-lee, W. L. McLean and M. Croft, Appl. Phys. Lett. 51, 619 (1987).ADSCrossRefGoogle Scholar
  8. 6.
    Y. Enomoto, T. Murakami, M. Suzuki, and K. Morwaki, Jap. J. Appl. Phys. 26, L1266 (1987).CrossRefGoogle Scholar
  9. 7.
    P. K. Mankiewich, J. H. Scofield, W. J. Skocpol, R. E. Howard, A. H. Dayem, and E. Good, Appl. Phys. Lett., 51, 1753 (1987).ADSCrossRefGoogle Scholar
  10. 8.
    D. K. Lathrup, S. E. Russek and R. A. Buhrman, Appl. Phys. Lett., 51, 1554 (1987).ADSCrossRefGoogle Scholar
  11. 9.
    H. Adachi, K. Hirochi. K. Setsune, M. Kitabatake, and K. Wasa, Appl. Phys. Lett., 51, 2263 (1987).ADSCrossRefGoogle Scholar
  12. 10.
    T. Terashima, K. lijima, K. Yamamoto, Y. Bando, and H. Mazaki, Jpn. J. Appl. Phys. 27, L91 (1988).ADSCrossRefGoogle Scholar
  13. 11.
    G.K. Wehner, Y.H. Kim, D.H. Kim, and A.M. Goldman, Appl. Phys. Lett., 52, 1187 (1988).ADSCrossRefGoogle Scholar
  14. 12.
    D.C. Bullock, C.T. Rettner, V.Y. Lee, G. Lim, R.J. Savoy, and D.J. Auerbach, in Thin Film Processing and Characterization of High-Temperature Superconductors, AlP Conference Proceedings No. 165, J.M.E. Harper, R.J. Colton, and L.C. Feldman, eds, American Institute of Physics (New York, 1988) pp. 71–79Google Scholar
  15. 12a.
    W.Y. Lee, J. Salem, V. Lee, C.T. Rettner, G. Lim, R. Savoy, and V. Deline, ibid. pp. 95–105.Google Scholar
  16. 13.
    R.L. Sandstrom, W.J. Gallagher, T.R. Dinger, R.H. Koch, R.B. Laibowitz, A.W. Klëinsasser, R.J. Gambino, B. Bumble, and M.F. Chisholm, Applied Phys. Lett. 53, 444 (1988).ADSCrossRefGoogle Scholar
  17. 14.
    M.M. Plechaty, B.L. Olson and G.J. Scilla, (unpublished).Google Scholar
  18. 15.
    R.L. Sandstrom, E.A. Giess, W.J. Gallagher, A. Scgmüller, E.l. Cooper, M. Chisholm, A.Gupta, S.Shinde, and R.B. Laibowitz Appl. Phys. Lett. (submitted).Google Scholar
  19. 16.
    J.W. Ekin, A.J. Panson, and B.A. Blankenship, Appl. Phys. Lett., 52, 331 (1988).ADSCrossRefGoogle Scholar
  20. 17.
    R. H. Koch, C. P. Umbach, G. J. Clark, P. Chaudhari, and R. B. Laibowitz, Appl. Phys. Lett. 51, 200 (1987).ADSCrossRefGoogle Scholar
  21. 18.
    R.H. Koch, C.P. Umbach, M.M. Oprysko, J.D. Mannhart, B. Bumble, G.J. Clarke, W.J. Gallagher, A. Gupta, A. Kleinsasser, R.B. Laibowitz, R.L. Sandstrom, and M.R. Scheuermann, Physica C 153–155, 1685 (1988).Google Scholar
  22. 19.
    R.H. Koch and W.J. Gallagher (to be published).Google Scholar
  23. 20.
    W.J. Gallagher, T.K. Worthington, T.R. Dinger, F. Holtzberg, D.L. Kaiser, and R.L. Sandstrom, Physica 148B, 228 (1987).Google Scholar

Copyright information

© Springer Japan 1989

Authors and Affiliations

  • W. J. Gallagher
    • 1
  • R. H. Koch
    • 1
  • R. L. Sandstrom
    • 1
  • R. B. Laibowitz
    • 1
  • A. W. Kleinsasser
    • 1
  • B. Bumble
    • 1
  • M. F. Chisholm
    • 1
  1. 1.IBM Thomas J. Watson Research CenterYorktown HeightsUSA

Personalised recommendations