US Patent 10249496 Narrowed feature formation during a double patterning process

Interconnect structures and methods of fabricating an interconnect structure. A first mandrel line, a second mandrel line, and a non-mandrel line between the first mandrel line and the second mandrel line are provided. A first sidewall spacer is formed adjacent to a section of the first mandrel line and is arranged between the section of the first mandrel line and the non-mandrel line. A first cut is formed that extends partially across the non-mandrel line adjacent to the first spacer to narrow a section of the non-mandrel line. The section of the first mandrel line is removed selective to the first sidewall spacer to form a second cut. An interconnect is formed using the non-mandrel line. The interconnect includes a narrowed section coinciding with a location of the narrowed section of the non-mandrel line.