Dual hard mask lithography process

Abstract

A first metallic hard mask layer over an interconnect-level dielectric layer is patterned with a line pattern. At least one dielectric material layer, a second metallic hard mask layer, a first organic planarization layer (OPL), and a first photoresist are applied above the first metallic hard mask layer. A first via pattern is transferred from the first photoresist layer into the second metallic hard mask layer. A second OPL and a second photoresist are applied and patterned with a second via pattern, which is transferred into the second metallic hard mask layer. A first composite pattern of the first and second via patterns is transferred into the at least one dielectric material layer. A second composite pattern that limits the first composite pattern with the areas of the openings in the first metallic hard mask layer is transferred into the interconnect-level dielectric layer.

Dependencies are inferred from the claim text.