International Business Machines Corporation
Structurally Stable Self-Aligned Subtractive Vias

Abstract:

Techniques for forming self-aligned subtractive top vias using a via hardmask supported by scaffolding are provided. In one aspect, a method of forming top vias includes: forming metal lines on a substrate using line hardmasks; patterning vias in the line hardmasks; filling the vias and trenches in between the metal lines with a via hardmask material to form via hardmasks and a scaffolding adjacent to and supporting the via hardmasks; removing the line hardmasks; and recessing the metal lines using the via hardmasks to form the top vias that are self-aligned with the metal lines. The scaffolding can also be placed prior to patterning of the vias in the line hardmasks. A structure formed in accordance with the present techniques containing top vias is also provided.