Patent ID: 8795540

Claim:
A method comprising: forming a photo resist pattern, wherein the photo resist pattern has a strip-shaped trench therein, with the strip-shaped trench encircled by the photo resist pattern, and wherein the strip-shaped trench comprises a middle portion, and end portions on opposite ends of the middle portion; performing a light-exposure on a first portion of the photo resist pattern, wherein a second portion of the photo resist pattern is not exposed to light, wherein the first portion of the photo resist pattern comprises portions of the photo resist pattern on opposite sides of the middle portion, and wherein the second portion comprises portions of the photo resist pattern that have edges exposed to the end portions of the strip-shaped trench; coating a photo-acid reactive material on the first portion and the second portion of the photo resist pattern; reacting the photo-acid reactive material with the photo resist pattern to form a film; and removing portions of the photo-acid reactive material that do not react with the photo resist pattern, wherein the film is left on the photo resist pattern.