Fabrication of intrinsic Josephson junction of bismuth-based cuprates

We have developed a new process for fabricating the intrinsic Josephson junctions of Bi-based cuprates with a size of 1 μm x 1.7 μm. The fabricated junctions have an S-shaped structure with four-terminal electrodes that enables us to measure the transport properties of the junctions without considering the effect of the contact resistance. The current-voltage characteristics exhibited clear hysteresis suggesting the absence of serious damage to the insulating layer during the fabrication process. The plasma frequency and crossover temperature were estimated from the parameters extracted from the transport measurements