US Patent 10366917 Methods of patterning variable width metallization lines

Methods of patterning metallization lines having variable widths in a metallization layer. A first mandrel layer is formed over a mask layer, with the mask layer overlying a second mandrel layer. The first mandrel layer is etched to form mandrel lines that have variable widths. The first non-mandrel trenches are etched in the mask layer, where the non-mandrel trenches have variable widths. The first mandrel lines are used to etch mandrel trenches in the mask layer, so that the mandrel lines and first non-mandrel lines define a mandrel pattern. The second mandrel layer is etched according to the mandrel pattern to form second mandrel lines, with the second mandrel lines having the variable widths of the plurality of first mandrel lines and the variable widths of the plurality of non-mandrel trenches.