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

Abstract

Self-aligned via patterning with multi-colored 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 including 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. A second layer of the interconnect structure is disposed above the first layer of the interconnect structure, the second layer including 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. First and second dielectric regions are 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 first dielectric region is composed of a first cross-linked photolyzable material, and the second dielectric region is composed of a second, different, cross-linked photolyzable material.