Patent ID: 8143194

Claim:
A method of polishing a target surface to be continuously polished of a tape-shaped substrate of an oxide superconductor material, said oxide superconductor material comprising said tape-shaped substrate, an intermediate layer with controlled crystalline directionality that is formed on said target surface of said tape-shaped substrate and an oxide superconductor thin film layer that is formed on said intermediate layer form an oxide superconductor member, said method comprising a polishing step of polishing said target surface while running said tape-shaped substrate continuously, said polishing step including an initial polishing process and a finishing polishing process, said initial polishing process comprising a first polishing process of carrying out random rotary polishing of said target surface of said tape-shaped substrate in at least one stage and thereby removing surface scratches formed by a rolling process and crystalline defects, and said finishing polishing process comprising a second polishing process of carrying out random rotary polishing of said target surface of said tape-shaped substrate in at least one stage and thereby finishing said target surface into a smooth and flat surface, wherein the average surface roughness Ra of said target surface becomes 2 nanometer or less and the in-plane directionality Δφ of said intermediate layer becomes 5° or less after said polishing step.