Method for producing substrates for superconducting layers

A substrate suitable for supporting an elongated superconducting element, the substrate comprising:

• a layered solid element, the layered solid element comprising
• a lower layer,
• lines of an upper layer,
• wherein the lines of the upper layer are placed adjacent to the lower layer and partially covers the lower layer,
• wherein a plurality of disruptive strips between the lines of the upper layer separate the lines of the upper layer,
• wherein undercut volumes are present between the lines of the upper layer and the lower layer and each undercut volume is formed along a disruptive strip.

An apparatus for producing a substrate suitable for supporting an elongated superconducting element, the apparatus capable of:

• providing a layered solid element, the layered solid element comprising
• a lower layer, and
• an upper layer,
• wherein the upper layer is placed adjacent to the lower layer and at least partially covers the lower layer,
• forming a plurality of disruptive strips in the upper layer thereby forming a plurality of exposed areas of the lower layer, where each exposed area is formed along a disruptive strip, and
• etching the exposed areas so as to form undercut volumes between the upper layer and the lower layer, where each undercut volume is formed along a disruptive strip, wherein an etchant is employed for which an etch rate for the lower layer is higher than an etch rate for the upper layer.