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

Abstract

A method of fabricating a semiconductor device, includes providing a semiconductor structure having a dielectric stack and a mandrel layer positioned on the dielectric stack. An array of sacrificial mandrel features are patterned into the mandrel layer and on top of an insulating layer of the dielectric stack. A self-aligned non-mandrel cut is formed adjacent a spacer element located adjacent to one of the sacrificial mandrel features. The sacrificial mandrel features are removed. One or more self-aligned mandrel cuts are formed in one or more of the plurality of trenches. Non-mandrel openings are formed on top of the insulating layer. Continuity line openings are etched into the dielectric stack, wherein the non-mandrel cut interrupts a first of the continuity line openings and the mandrel cut is disposed to interrupt a second of the continuity line openings. Metal lines are formed in the continuity line openings, except where the non-mandrel cut and mandrel cut are disposed.