International Business Machines Corporation
Litho-etch-litho-etch with self-aligned blocks

Abstract:

A method for fabricating a semiconductor device includes forming a plurality of mandrel cuts from a first set of mandrels of a base structure using lithography, surrounding the first set of mandrels and a second set of mandrels of the base structure with spacer material to form mandrel-spacer structures, forming a flowable material layer on exposed surfaces of the mandrel-spacer structures, and performing additional processing, including forming a plurality of dielectric trenches within the base structure based on patterns formed in the flowable material layer.