US Patent 12094774 Back-end-of-line single damascene top via spacer defined by pillar mandrels

Embodiments of the present invention are directed to fabrication methods and resulting structures having a back-end-of-line (BEOL) single damascene (SD) top via spacer defined by pillar mandrels. In a non-limiting embodiment of the invention, a first conductive line is formed in a first dielectric layer. A mandrel is formed over the first conductive line and a spacer is formed on a sidewall of the mandrel. A portion of a second dielectric layer is recessed to expose a top surface of the spacer and a top surface of the mandrel and the mandrel is removed. The spacer prevents damage to the second dielectric layer while removing the mandrel. The mandrel is replaced with a conductive material. A first portion of the conductive material defines a via and a second portion of the conductive material defines a second conductive line. The via couples the first conductive line to the second conductive line.