Mask overhang reduction or elimination after substrate etch

A method of forming IC devices having filled etched features, comprising:

• providing a substrate having a top semiconductor surface and a bottom surface;
• forming a patterned masking layer comprising at least one masked region having at least one masking layer thereon and at least one feature region bounded by said masking layer;
• etching to form an etched feature in said substrate, wherein undercutting during said etching results in formation of at least one mask overhang region over a surface portion of said etched feature recessed relative to an outer edge of said masking layer;
• a pullback etch process exclusive of any additional patterning step following said etching for laterally etching said masking layer, wherein conditions for said pullback etch process are selected to retain at least a portion of said masking layer and reduce a length of said mask overhang region by at least 50% or eliminate said mask overhang region, and
• filling said etched feature after said pullback etch process to form a filled etched feature.