Patent ID: 8158334

Claim:
A method of forming a lithographic pattern comprising: forming an underlayer on a substrate; forming a hard mask layer having a bottom surface in physical contact with a surface of said underlayer; applying a first photoresist and lithographically patterning said first photoresist with a first pattern including a first sub-pattern and a second sub-pattern, wherein said first sub-pattern said second sub-pattern contain at least one instance of a unit pattern; transferring said first pattern into said hard mask layer, wherein a first set of openings replicating said first sub-pattern and a second set of openings replicating said second sub-pattern are formed within said hard mask layer; applying a second photoresist on said hard mask layer and said underlayer, wherein a material layer selected from said second photoresist and an planarizing material layer fills each of said first set of openings and each of said second set of openings; lithographically patterning said material layer with a second pattern, wherein said second set of openings in said hard mask layer is filled with said material layer while said surface of said underlayer is physically exposed within said first set of openings in said hard mask layer; and transferring a composite pattern of said first pattern and said second pattern into said underlayer, wherein said composite pattern includes openings within said underlayer that underlie said first set of openings in said hard mask layer and does not include any opening underneath said second set of openings in said hard mask layer.