MANUFACTURE OF SUPERCONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain an excellent surface flatness by preparing a laminated substrate made by forming an oxide superconductor film having a specified thickness or above on an insulator substrate by a liquid phase epitaxial method, and then mechanically polishing the oxide superconductor film on a rotating polishing disc using a specified polishing liquid. SOLUTION: An MgO substrate 15 is brought into contact with the surface of a YBCO melted liquid in a crucible 11 and is gradually pulled up while being turned, to form a YBCO film (oxide superconductor film) 16 of the thickness of 1μm or above on the surface of the MgO substrate 15. The YBCO film 16 having an unevenness formed on the surface of the MgO substrate 15 is mechanically polished by a grinding disc 25 to be flattened. Since the YBCO film 16 deteriorates in its characteristics when it is brought into contact with water, use of water should be avoided. Therefore, a liquid containing no water dispersed with polishing grains having the average grain diameter of 0.05μm or below is used for a polishing liquid. For example, an oil slurry made by dispersing alumina grains in hydrocarbon-system oil mainly of petroleum naphtha is used.