Metal working – Method of mechanical manufacture – Assembling or joining
Patent
1982-11-29
1984-09-11
Hearn, Brian E.
Metal working
Method of mechanical manufacture
Assembling or joining
29571, 29578, 148 15, 148174, 148180, 357 5, H01L 3922, H01L 21265
Patent
active
044701900
ABSTRACT:
A method for changing Josephson device parameters, e.g., the critical current of a Josephson junction. The method comprises incorporating doping material into the device, or part of the device, followed by a light anneal. Exemplary dopants include In, Sn, Sb, Te, Bi, Hg, Mg, Li, Cd, Na and Ta, with In, Sn, and Sb being preferred dopants for changing the critical current of a Josephson junction having a Pb-containing counter electrode. The dopant can be incorporated into the device by in-diffusion after deposition onto the surface, by ion implantation, or by any other convenient method. The amount of dopant required is typically small. For example, deposition of a Sn layer of 0.05 nm effective thickness onto the 200 nm thick Pb-Sb(1.5 wt. %) counter electrode of a cross-type Josephson junction, and annealing at 80.degree. C. for about 3 hours, resulted in an increase in the critical current of the junction by a factor of about 2.5. The method is considered to have wide applicability in the manufacture of Josephson devices, and can be applied globally, i.e., to all the devices on a wafer or chip, or locally, i.e., to selected devices.
REFERENCES:
patent: 3521133 (1970-07-01), Beam
patent: 3897276 (1975-07-01), Kondo
patent: 3966501 (1976-06-01), Nomura et al.
patent: 4050967 (1977-09-01), Rosnowski et al.
patent: 4176365 (1979-11-01), Kroger
patent: 4263603 (1981-04-01), Jillie
Harris, "Preperation of Superconducting Weak Links . . . by Ion Implantation". IEEE Trans Magn. vol. May 11, No. 2, Mar. 1975, pp. 785-788.
"An Overview of Materials and Process Aspects of Josephson Integrated Circuit Fabrication", I. Ames, IBM Journal of Research and Development, vol. 24(2), pp. 188-194 (1980).
"Niobium Oxide-Barrier Tunnel Junction", R. F. Broom et al., IEEE Transactions on Electron Devices, vol. ED-27(10), pp. 1998-2008, Oct. 1980.
"Electron Irradiation Effects in Lead-Alloy Josephson Junctions", by Y. H. Lee and P. R. Brosious, Applied Physics Letter, vol. 40(4), 1982, pp. 347-349.
Projected Range Statistics, 2nd ed. Dowden, Hutchinson and Ross, Inc. (1975) by J. F. Gibbons et al.
Metals Reference Book, vol. II, 4th edition, Plenum Press, 1967, by C. J. Smithells.
Constitution of Binary Alloys, 2nd edition, McGraw-Hill, 1958.
"Computing at 4 Degrees Kelvin", by W. Anacker, IEEE Spectrum, May 1979, pp. 26-37.
"Fabrication Process for Josephson Integrated Circuits", by J. H. Greiner et al., IBM Journal of Research and Development vol. 24(2), Mar. 1980, pp. 195-205.
"Advanced Superconducting Materials for Electronic Applications", by M. R. Beasley, IEEE Transactions on Electron Devices, vol. ED-27(10), pp. 2009-2015.
"Effect of Process Variables on Electrical Properties of Pb Alloy Josephson Junctions", by R. F. Broom et al., IBM Journal of Research and Development, vol. 24(2), Mar. 1980, pp. 206-211.
Fulton Theodore A.
Pei Shin-Shem
AT&T Bell Laboratories
Hearn Brian E.
Hey David A.
Pacher Eugen E.
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