International Business Machines Corporation
VIA-VIA SPACING REDUCTION WITHOUT ADDITIONAL CUT MASK

Abstract:

A method is presented for employing double-patterning to reduce via-to-via spacing. The method includes forming a mandrel layer over a substrate, forming sacrificial hardmask layers over the mandrel layer defining a litho stack, creating a pattern in the litho stack, the pattern having a narrow section connecting two wider sections to define a substantially hour-glass shape, depositing a spacer assuming a shape of the pattern, and etching the litho stack to expose the mandrel layer and metal lines, wherein the metals lines define sharp distal ends reducing a distance between the metal lines.