Mask overhang reduction or elimination after substrate etch

Abstract

A method of forming IC devices includes providing a substrate and forming a patterned masking layer including at least one masked region having at least one masking layer, and a feature region bounded by the masking layer. Etching forms an etched feature in the substrate, wherein undercutting during the etching forms at least one mask overhang region over a surface portion of the etched feature that is recessed relative to an outer edge of the masking layer. A pullback etch process exclusive of any additional patterning step laterally etches the masking layer. The conditions for the pullback etch retain at least a portion of the masking layer and reduce a length of the mask overhang region by at least 50%, or eliminate the mask overhang region entirely. The etched feature is then filled after the pullback etch process to form a filled etched feature.

Dependencies are inferred from the claim text.