Line-end extension method and device

A method comprising:

• forming a hard mask layer on a target layer, the target layer disposed between a substrate and the hard mask layer;
• forming a patterned photoresist on a plurality of first regions of the hard mask layer;
• forming a plurality of line-end extension regions extending outwardly from ends of the plurality of first regions by irradiating the hard mask layer with a plurality of ion beams each having a non-zero ion beam angle with respect to a direction orthogonal to the hard mask layer, the patterned photoresist blocking at least a portion of the plurality of ion beams from reaching the plurality of line-end extension regions, wherein the plurality of line-end extension regions includes a first and a second line-end extension regions extending along the same axis and arranged end-to-end, the first and second line-end extension regions being separated by a gap;
• removing the patterned photoresist;
• exposing portions of the target layer by removing portions of the hard mask layer, the removing portions of the hard mask layer including removing a portion of the plurality of line-end extension regions at a rate that is higher than a rate at which a portion of the plurality of first regions of the hard mask layer are removed;
• and
• forming a patterned feature in the target layer by removing the exposed portions of the target layer.

A method, comprising:

• forming a patterned photoresist on a plurality of first regions of a hard mask layer, the plurality of first regions extending along the same axis for a length (L2) and terminating at respective ends,
• wherein the plurality of first regions comprises three parallel line regions extending along the same axis without intersecting one another,
• wherein a first line region and a third line region are disposed above and below, respectively, of a second line region,
• wherein the second line region, positioned between the first and third line regions, comprise a first line-end extension region and a second line-end extension region extending along the same axis and arranged end-to-end,
• wherein the first and second line-end extension regions are separated by a gap, and wherein the gap faces a continuous portion of each of the first and third line regions extending along the same axis;
• forming the first and second line-end extension regions in the hard mask layer, the first and second line-end extension regions extending laterally outward from the ends of the second line region of the hard mask layer, the forming the first and second line-end regions including changing a physical property of the hard mask layer at the first and second line-end extension regions;
• removing the patterned photoresist;
• removing portions of the hard mask layer, thereby exposing portions of a target layer, the removing portions of the hard mask layer including removing a portion of the first and second line-end extension regions at a rate that is higher than the rate at which a portion of the plurality of first regions of the hard mask layer is removed;
• and
• forming a patterned feature in the target layer by removing the exposed portions of the target layer.