YBa2Cu3O7 nanobridges fabricated by direct-write electron beam lithography

Abstract

A direct method for nondamaging, nanometer-scale patterning of high Tc superconductor thin films is presented. We have fabricated superconducting nanobridges in high-quality, epitaxial thin-film YBa2Cu3O7 (YBCO) by combining direct-write electron beam lithography and an improved aqueous etchant. Weak links with both length and width dimensions less than 20 nm have exhibited critical currents at 77 K of 4–20 μA and IcRn products of 10–100 μV which compare favorably with results for other YBCO junction technologies. We have used this technique in the fabrication of a shock-wave pulse former as an initial demonstration of its applicability to monolithic superconductive electronics.