A study of planar structures formed on the modified Al$_{2}$O$_{3}$ surfaces determining the topology of superconducting elements during YBa$_{2}$Cu$_{3}$O$_{7-d}$ deposition

We investigate the structural and electrical properties of planar superconducting structures based on the YBa$_{2}$Cu$_{3}$O$_{7-d}$ (YBCO) epitaxial films obtained by preliminary modification of the substrate surface. A special master mask was formed on the substrates, so that, at the standard YBCO film deposition onto such a substrate, an insulator layer grew in the modified areas and a superconducting film, in the unmodified ones. Thus, the planar superconducting structure of a desired topology was formed, and the YBCO deposition finished the process. Using this technique, YBCO bridges with widths of 4, 10, and 50 $\mu$m on films of different thicknesses and a planar inductive coil were formed. The superconducting transition temperature of the bridges was about 90 K, and the critical current density at a temperature of 77 K was up to 3 MA/cm$^2$. The $Q$ factor of the planar inductive coil at a frequency of 85 MHz was 53000 at a temperature of 77 K.