SNS-DC-SQUIDS AND FLUX TRANSFORMERS FOR INTEGRATED MAGNETOMETERS IN FLIP-CHIP TECHNIQUE

-delta/Ag/YBa(2)Cu(3)O(7-delta)Josephson-Junctions across steps in MgO substrates were used to fabricate SNS-DC-SQUIDs in the step-and-gap g eometry [1]. The necessary break of the YBa2Cu3O7-delta-film at the st ep was confirmed by transmission electron microscopy investigations. T he removal of the Ag-layer eliminates the shunt resistance on top of t he HTSC (Fig. 1) which increases the normal resistance R(N) by more th an two orders of magnitude with only a slight reduction in I-C. The ju nctions can be described by the SINS-formalism, which allows high I(C) R(N)-products with large values of the normal resistances R(N). For th in-film flux transformer epitaxial YBa2Cu3O7-delta/SrTiO3/YBa2Cu3O7-de lta trilayers were grown using a co-sputter process. Test coils exhibi ted a current density in excess of 810(5) A/cm(2) and insulation resi stivities of 10(8) Omega cm at 77 K. By coupling the flux transformers to SQUIDs using a flip-chip technology the magnetic field response we re increased by a factor of 9.