Proximity-coupled weak links in YBCO films

Measurements of SNS planar microbridges made from high-quality in situ sputtered YBCO films were made. The devices were fabricated using single superconducting films with a patterned gap bridged by sputter-deposited silver. A number of devices exhibit supercurrents and microwave-induced steps in the current-voltage characteristics. In the best devices the normal state resistance is consistent with expected values. The consequences of the anisotropy of YBCO and the effects of various fabrication techniques on device performance and yield are discussed.