Superconductive interconnect structure

A method for forming a superconducting interconnect structure of an integrated circuit, comprising:

• a. forming a first entity on a substrate by:
• a1. providing a substrate,
• a2. forming a first superconductive layer of a first superconductive material having a first critical temperature on the substrate,
• a3. forming a layer of a first dielectric material over the first superconductive layer,
• a4. removing parts of the layer of the first dielectric material and of the first superconductive layer, said parts extending from a bottom surface of the first superconductive layer to a top surface of the first dielectric material, so as to form a pattern comprising a first set of line structures having a top surface, comprising:
• a first set of superconductive line structures, and
• a first set of line structures made of the first dielectric material, aligned with and overlying the first set of superconductive line structures, and comprising the top surface,
• a5. forming a second dielectric material, different from the first dielectric material, over and between the line structures of the first set,
• a6. planarizing the second dielectric material so that a top surface of the second dielectric material is coplanar with the top surface of the first set of line structures, and thereafter
• a7. forming a layer formed of a third dielectric material over the first set of line structures and the second dielectric material,
• thereby forming the first entity,
• b. providing a patterned mask over the first entity, the pattern comprising at least one opening overlapping with an underlying superconductive line structure of the first set of superconductive line structures for forming at least one via hole in the first dielectric material and the layer formed of the third dielectric material,
• c. transferring the pattern of the patterned mask into the first dielectric material and into the layer formed of the third dielectric material, so as to form the at least one via hole extending through the first dielectric material and the layer formed of the third dielectric material, thereby exposing part of the underlying superconductive line structure,
• d. removing the patterned mask, thereby exposing a perforated surface, and
• e. forming a superconductive unit made of one or more superconductive materials, each having a critical temperature within 1K of the first critical temperature, over the perforated surface thereby also forming at least one via by filling the at least one via hole, the at least one via extending through the first dielectric material and the layer formed of the third dielectric material, such that the formed superconductive unit physically contacts the underlying first set of superconductive line structures.