A technique relates to a structure. An under-bump-metallization (UBM) structure includes a first region and a second region. The first and second regions are laterally positioned in the UBM structure. The first region includes a superconducting material. A substrate opposes the UBM structure. A superconducting solder material joins the first region to the substrate and the second region to the substrate.

A technique relates to a structure. An under-bump-metallization (UBM) structure includes a first region and a second region. The first and second regions are laterally positioned in the UBM structure. The first region includes a superconducting material. A substrate opposes the UBM structure. A superconducting solder material joins the first region to the substrate and the second region to the substrate.