Patent ID: 8546069

Claim:
A photolithography method comprising: forming a first layer of a first photoresist over a substrate, said first photoresist is photosensitive to a radiation having an imaging wavelength; forming a second layer of a second photoresist over said first layer, said second photoresist comprising a polymer containing an absorbing moiety rendering said polymer absorbing said radiation; exposing said second layer to a first dose of said radiation through a first patterned mask, said first patterned mask comprising a dense pattern; developing said second layer in an aqueous base solution to remove base soluble regions of said second layer and reveal sections of said first layer, wherein a first relief image is formed in said second layer, said first relief image comprising said dense pattern; exposing at least one said revealed section of said first layer to a second dose of said radiation through a second patterned mask, wherein said second patterned mask comprises an isolated or a semi-isolated pattern; removing said first relief image and base soluble regions of said first layer to form a second relief image in said first layer, said second relief image comprising said isolated or semi-isolated pattern; and after said exposing said second layer and before said developing, baking said second layer at a first temperature, rendering at least one other region of said second layer substantially soluble in said aqueous base.