Fabrication of superconducting quantum interference devices based on Bi2Sr2CaCu2O8+δ constriction-type junctions
Abstract
The direct-current superconducting quantum interference devices (dc-SQUIDs) based on Superconducting-Constriction-Superconducting (S-C-S) junctions have been successfully fabricated and studied from caxis oriented Bi2Sr2CaCu2O8+δ (Bi-2212) films grown on MgO substrate by combined sedimentation-deposition, liquid phase sintering and annealing technique. Films had a superconducting transition temperature, Tc ¬ 57 K. Reduction of Tc never larger than 4 K indicates that the superconducting properties of the films are not appreciably altered after patterning. However, a broadening of the transition width and a decrease in the slope at the metallic regime of the R-T curve was observed. These changes in the properties can be attributed to the photoresist contamination and the effect of the etchant on the film.