Passivation of YBCO Step Edge Josephson Junction Using Spray‐Coated Photoresist Layer

In this study, a simple and low‐cost method is presented to passivate YBCO step edge Josephson junctions using spray‐coated photoresist fabricated on STO (100) substrate. It is found that the long‐term stability and performance of the devices are significantly influenced by environmental degradation. In order to protect the device from moisture and enhance its stability, it is passivated using an S1813 photoresist layer using the spray coating method, and its impact on key junction parameters, including critical temperature, critical current, and normal state resistance, is studied. Unlike traditional or vacuum‐based methods, which are costly or struggle with uneven surfaces, spray coating ensures uniform coverage on nonplaner geometries such as step edge. This makes the process faster, cheaper, and more practical for scalable superconducting device operation at cryogenic temperatures.