Transport properties of epitaxial YBa2Cu3Ox films at step edges

To study the current‐carrying capability of interconnections between conducting planes in a YBa2Cu3Ox‐insulator multilayer system, the transport properties of laser‐deposited YBa2Cu3Ox striplines at different step edges in 〈100〉 SrTiO3 substrates were investigated. Step edges with various heights between 100 and 800 nm and slope angles a=2.5°, 10°, 25°, 40°, and 65° were fabricated by Ar+ ion milling. The previous ion milling of one part of the substrate does not affect the crystal growth and the transport properties of the superconductor, which has been checked by electrical and x‐ray measurements. Two ways for a high transport current between conducting planes were realized. At flat angles up to 30°, a critical current density of ≳106 A/cm2 at 77 K can be achieved for a step stripline with film thickness d0 smaller than the step height h. If the film thickness d0 is larger than the step height, high superconducting current densities can also be achieved for a≳65°.