Patent ID: 8053172

Claim:
A photolithography method comprising: forming a first layer of a first photoresist on a substrate, said first photoresist comprising a first polymer and a first photosensitive acid generator, said first photosensitive acid generator producing acid upon exposure to radiation having a wavelength or range of wavelengths; forming a second layer of a second photoresist directly onto said first layer, said second photoresist comprising a second polymer and a second photosensitive acid generator, said second photosensitive acid generator producing acid upon exposure to said radiation, said second polymer comprising an absorbing moiety resulting in said second polymer absorbing said radiation; patternwise imaging said second layer through a first mask, resulting in exposing at least one region of said second layer to a first dose of said radiation, resulting in said second photosensitive acid generator producing acid in said exposed at least one region of said second layer; developing said second layer in an aqueous base solution, resulting in removal of base-soluble regions of said second layer, wherein a first relief pattern from said second layer remains following said removal; exposing said first relief pattern and said first layer to a second dose of said radiation through a second mask, resulting in exposing at least one region of said first relief pattern to said second dose of radiation, said polymer in said first relief pattern absorbing a portion of said second dose of radiation, resulting in a fraction of said second dose of radiation passing through said at least one region of said first relief pattern and exposing at least one region of said first layer to said fraction of said second dose of radiation, resulting in said first photosensitive acid generator producing acid in said exposed at least one region of said first layer; and removing said first relief pattern and base-soluble regions of said first layer, wherein a second relief pattern from said first layer remains following said removing.