Patent ID: 8021828

Claim:
A photolithography method comprising: forming a first layer of a first photoresist onto a substrate, said first photoresist comprising a first polymer and a first photosensitive acid generator; 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 polymer having at least one repeating unit comprising a moiety selected from the group consisting of: wherein R is selected from the group consisting of hydrogen, halogens, alkyl groups, aromatic groups, and combinations thereof, and wherein R1 is selected from the group consisting of hydrogen. halogens, alkyl groups, and combinations thereof; patternwise imaging said second layer through a patterned mask, resulting in exposing at least one first portion of said second layer to a first dose of radiation having a wavelength or range of wavelengths, wherein at least one second portion of said second layer is not exposed to said radiation, said second photosensitive acid generator producing an acid catalyst in said exposed at least one first portion of said second layer, resulting in rendering said exposed first portion soluble in aqueous base developer; removing said at least one first portion of said second layer, resulting in revealing at least one first region of said first layer directly beneath said first portion, said at least one second portion of said second layer remaining after said removing resulting in forming a structure having masked regions comprising said at least one second portion of said second layer and unmasked regions comprising gaps formed by said removing said at least one first portion of said second layer; exposing said structure and said at least one first region of said first layer to a second dose of said radiation, said masked regions of said structure shielding, from said second dose of radiation, at least one second region of said first layer directly beneath said masked regions, resulting in said first photosensitive acid generator producing an acid catalyst in said exposed at least one first region of said first layer and said second photosensitive acid generator producing an acid catalyst in said structure; and removing said structure and base-soluble regions of said first layer.