Microwave and DC-transport in YBa2Cu3O7 ramp-edge Josephson junction arrays

The chip-to-chip and the on-chip spread of the transport properties like the critical current and the normal state resistance of Josephson junctions from high-temperature superconductors (HTS) are very important for many applications. To analyse the on-chip spread we prepare and investigate Josephson junction arrays with up to 30 Josephson junctions in series, where each Josephson junction can be measured individually. The preparation process consists of laser deposition, conventional photolithography and argon ion etching in a parallel-plate reactor. We use Josephson junctions in ramp-edge geometry on 1 x 1 cm(2) LaAlO3-substrates. As barrier material we use PrBa2Cu3O7. We measure current-voltage (I-V) curves and the differential resistance. This way we determine the temperature-dependent spread of the electronic properties in the ramp-edge Josephson junctions. We analyse different contributions to the spread. Measurements under influence of RF-radiation illustrate the consequences of the observed spread in the critical current. (C) 1999 Elsevier Science B.V. All rights reserved.