Fabrication of submicrometer features in Y-Ba-Cu-O superconducting thin films

The authors explored some of the processes required to fabricate superconducting devices in Y-Ba-Cu-O thin films. Photolithography was used to define superconducting wires with dimensions from several micrometers to less than one micrometer in films grown both by laser and electron-beam deposition. Patterns were transferred with a variety of techniques including lift-off, chemical etching, and argon ion milling. Low-resistance contacts were reliably made by in situ Ar ion beam presputter and Au or Ag deposition. Submicrometer wires produced with these processes behaved as scaled-down bulk superconducting films; wire properties were determined largely by initial film morphology and wire geometry. No naturally occurring weak link behavior was observed in wires down to 0.5 mu m in width. The fabrication process and the electrical behavior of the resulting wires are discussed.<>