Intrinsic Josephson junctions on high-quality BSCCO-2212/2223 superlattice thin films grown by MOCVD

We report on the successful preparation of intrinsic Josephson junctions on high-quality BSCCO-2212/2223 superlattice thin films grown by MOCVD. The surface of as-grown films was very smooth with the roughness of the order of a half unit cell. Mesas were effectively structured on the film by the liquid-nitrogen-cooled dry etching method. A typical I-V characteristic in the c-axis direction of a BSCCO film shows the hysteresis and multiple resistive branches. The number of branches is consistent with that of junctions calculated from the height of a mesa structure. This indicates that BSCCO-2212/2223 superlattice films consist of a series array of S(CuO₂ bilayer)/I(SrO, BiO layers)/S(CuO₂ trilayer) junction. The formation of stacked Josephson junctions was also confirmed by the temperature dependence and the magnetic field dependence of Ic.