High-T/sub c/ SNS junctions for multilevel integrated circuits

High-quality superconductor-normal metal-superconductor (SNS) Josephson microbridges have been fabricated in a variety of configurations across the edge of steps in a manner that is consistent with a multilevel integrated circuit process. The best junctions have critical current-resistance products of 1-3 mV at 4 K and 100-500 mu V at 77 K, useful values for many analog and digital applications not requiring hysteretic junctions. The DC transport characteristics of the junctions and issues of reproducibility and uniformity are discussed. In particular, a simple theoretically based analysis of junction parameter spread is presented. >