| 摘要 |
PURPOSE:To prevent a superconducting film from being damaged and to prevent the critical current value from being decreased, by forming a protective film of a dielectric material on the thin superconducting film, selectively forming an etching mask layer on the protective film and selectively etching away the protection film and the superconducting film. CONSTITUTION:After formation of a thin superconducting film 2 on a substrate 1, a protection film 4 of a dielectric material is formed on the thin superconducting film 2. An etching mask layer 3 is then formed selectively on the protective film 4 so that the protective film 4 and the thin superconducting film 2 are etched away selectively. For example, a thin superconducting film 2 of Nb having a thickness of 2,000Angstrom is formed on a silicon substrate 1 by the spattering process and then a protective film 4 of SiO is formed to 500Angstrom . A photoresist pattern 3 is then formed to provide a mask used for etching and patterning the protective film 4 and the thin superconducting film 2 by means of the reactive ion etching using CF4 and O2 (5%). During this process, the ions are blocked by the protection film 4 and do not damage the thin superconducting film 2.
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