Self-aligned litho-etch-litho-etch mandrel cut process for advanced FINFET interconnect

A method of fabricating a semiconductor device, comprising:

• providing a semiconductor structure having a dielectric stack and a mandrel layer positioned on the dielectric stack;
• patterning an array of sacrificial mandrel features into the mandrel layer and on top of an insulating layer of the dielectric stack;
• forming spacer elements located adjacent each of the sacrificial mandrel features;
• forming a self-aligned non-mandrel cut adjacent to one of the spacer elements adjacent to one of the sacrificial mandrel features,
• filling the self-aligned non-mandrel cut with a first placeholder material, wherein a top surface of the first placeholder material is substantially uniform with a top surface of the adjacent spacer element;
• removing the sacrificial mandrel features, wherein removal of the sacrificial mandrel features creates a plurality of trenches located between spacer elements;
• forming one or more self-aligned mandrel cuts in one or more of the plurality of trenches after removal of the sacrificial mandrel features,
• filling the self-aligned mandrel with a second placeholder material, wherein the second placeholder material contacts adjacent spacer elements, wherein a top surface of the second placeholder material is substantially uniform with a top surface of the adjacent spacer elements;
• forming non-mandrel openings on top of the insulating layer;
• etching continuity line openings into the dielectric stack, wherein the self-aligned non-mandrel cut is disposed to interrupt a first of the continuity line openings and the one or more self-aligned mandrel cut cuts are disposed to interrupt a second of the continuity line openings;
• and
• forming metal lines in the continuity line openings, except where the self-aligned non-mandrel cut and the one or more self-aligned mandrel cuts are disposed.