Self-aligned via and plug patterning with photobuckets for back end of line (beol) interconnects

Abstract

Self-aligned via and plug patterning with photobuckets for back end of line (BEOL) interconnects is described. In an example, an interconnect structure for an integrated circuit includes a first layer of the interconnect structure disposed above a substrate, the first layer having a first grating of alternating metal lines and dielectric lines in a first direction. The dielectric lines have an uppermost surface higher than an uppermost surface of the metal lines. The integrated circuit also includes a second layer of the interconnect structure disposed above the first layer of the interconnect structure. The second layer includes a second grating of alternating metal lines and dielectric lines in a second direction, perpendicular to the first direction. The dielectric lines have a lowermost surface lower than a lowermost surface of the metal lines of the second grating. The dielectric lines of the second grating overlap and contact, but are distinct from, the dielectric lines of the first grating. The integrated circuit also includes a region of dielectric material disposed between the metal lines of the first grating and the metal lines of the second grating, and in a same plane as upper portions of the dielectric lines of the first grating and lower portions of the dielectric lines of the second grating. The region of dielectric material is composed of a cross-linked photolyzable material.