3D intrinsic Josephson junctions using c-axis thin films and single crystals

We report successful fabrication of 3D intrinsic Josephson junctions (IJJs) using c-axis YBCO thin films of 800 nm thickness and Bi-2212 single-crystal whiskers. The stacks of IJJs were prepared by a lateral focused ion beam etching method. The width depending on the required junction size and the full depth of film thickness were patterned in a micro area from the normal direction etching. By tilting the sample stage up to 90 degrees, two grooves of the bridge were etched from the lateral direction in accordance with the required junction size. The junctions did not show any degradation of critical current density (J(c)) down to an in-plane area of 0.5 mu m(2).