Patent ID: 8158014

Claim:
A method of forming a patterned structure comprising: forming a stack of, from bottom to top, a second photoresist and a first photoresist on a substrate; lithographically patterning said first photoresist with a first pattern, wherein a top surface of said second photoresist is exposed in an area of said first pattern; and lithographically forming a second pattern in said second photoresist, wherein said second pattern includes a plurality of line troughs, wherein each of said plurality of line troughs includes a narrow portion having a first width, and wherein at least one of said plurality of line troughs includes a bulge portion having a second width greater than said first width, wherein said bulge portion is formed underneath said area of said first pattern, wherein said second pattern is formed by simultaneously lithographically exposing said first photoresist having said first pattern and said second photoresist with a light exposure pattern generated by a lithographic mask containing a pattern of a set of parallel lines of a constant width.