Claims
- 1. In a method of preparing metallic oxide films on a substrate through the sputtering of copper oxide-based target material onto a heated substrate in a closed reactor containing a sputtering gas comprising O.sub.2, and residual impurity amounts of H.sub.2 O vapor having a pressure below approximately 1.0.times.10.sup.-3 mbar, wherein the improvement comprises a sputtering gas containing added H.sub.2 O vapor, to provide a total H.sub.2 O vapor pressure in the reactor of from 7.times.10.sup.-3 mbar to 266.times.10.sup.-3 mbar, and a thin copper-oxide based film having superconducting capability is in-situ deposited on a substrate disposed at a 90.degree. angle to the target surface, at a substrate temperature of from 550.degree. C. to 800.degree. C., and slowly cooling the sputtered film at a rate of from 50.degree. C./hr to 200.degree. C./hr, wherein substantial target erosion does not appreciably affect critical temperature values of the deposited film as deposition continues with time, and after cooling, the stoichiometry of the film will not be deficient in oxygen.
- 2. The method according to claim 1, where the target and deposited film consist of YBa.sub.2 Cu.sub.3 O.sub.7 material, the target material being in pressed powder form.
- 3. The method according to claim 1, where the substrate temperature is from 560.degree. C. to 650.degree. C.
- 4. The method according to claim 1, where the substrate is LaAlO.sub.3, in single crystal form.
- 5. The method according to claim 1, where the addition of H.sub.2 O vapor provides a total H.sub.2 O vapor pressure of from 7.times.10.sup.-3 mbar to 30.times.10.sup.-3 mbar.
- 6. The method according to claim 1, where the sputtering gas also contains Ar or other inert gas, the reactor is selected from an rf magnetron and dc magnetron type, and the addition of H.sub.2 O vapor provides a total H.sub.2 O vapor pressure of from 17.times.10.sup.-3 mbar to 266.times.10.sup.-3 mbar.
Government Interests
The invention described herein was made in the performance of work under a U.S.A.F. contract identified as Air Force Contract F49620-88-C-0039, in which the Government has rights.
US Referenced Citations (6)
Foreign Referenced Citations (3)
Number |
Date |
Country |
2-92809 |
Apr 1990 |
JPX |
3-5306 |
Jan 1991 |
JPX |
WO8911736 |
Nov 1989 |
WOX |
Non-Patent Literature Citations (1)
Entry |
Gavaler et al., Physica B, vols. 165 and 166, pp. 1513-1514, Aug. 16-22, 1990, "Optimization of T.sub.c and J.sub.c in Sputtered YBCO Films". |