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

The authors have explored some of the processes required to fabricate superconducting devices in Y-Ba-Cu-O thin films. They have employed photolithography to define superconducting wires with dimensions from several micrometers to less than one micrometer in films grown both by laser and electron-beam deposition. They transfer patterns with a variety of techniques including lift-off, chemical etching, and argon ion milling. Low resistance contacts are 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 are determined largely by initial film morphology and wire geometry. No naturally occurring weak link behavior has been observed in wires down to 0.5μm in width. The fabrication processes and the electrical behavior of the resulting wires are discussed