Resists for lithography

Abstract

New routes involving multi-step reversible photo-chemical reactions using two-step techniques to provide non-linear resist for lithography are described in this disclosure. They may provide exposure quadratically dependant on the intensity of the light. Several specific examples, including but not limited to using nanocrystals, are also described. Combined with double patterning, these approaches may create sub-diffraction limit feature density.

We claim: 
     
         1 . A resist comprising:
 at least one matrix material; and   at least one photoactive material carried by said matrix material, said photoactive material producing chemical species in at least one plural-step reaction, said chemical species changing the solubility of said resist,   wherein said chemical species production is non-linearly dependent on the intensity of light.   
     
     
         2 . The resist of  claim 1  wherein said photoactive material comprises nanocrystals. 
     
     
         3 . The resist of  claim 1  wherein said photoactive material comprises a semiconductor. 
     
     
         4 . The resist of  claim 1  wherein said photoactive material comprises at least one organic molecule. 
     
     
         5 . The resist of  claim 1  wherein said photoactive material comprises at least one inorganic molecule. 
     
     
         6 . The resist of  claim 1  further including an acid generator. 
     
     
         7 . The resist of  claim 1  wherein the acid generator forms an acid in a manner that is quadratically dependent on the intensity of light. 
     
     
         8 . The resist of  claim 1  wherein the solubility of said resist is changed by chain-scission induced by light through at least one plural-step reaction, said chain-scission being quadratically dependent on the intensity of light. 
     
     
         9 . The resist of  claim 1  wherein the solubility of said resist is changed by cross-linking induced by light through at least one plural-step reaction, said cross-linking being quadratically dependent on the intensity of light. 
     
     
         10 . The resist of  claim 1  wherein said plural-step reaction comprises forming intermediate excited states. 
     
     
         11 . The resist of  claim 1  wherein said plural-step reaction comprises a first step which forms a first intermediate result and a second step forming a second intermediate result, said second intermediate result alone or in combination with said first intermediate result leading to said change in solubility. 
     
     
         12 . The resist of  claim 1  wherein said matrix material comprises a polymer or a molecular glass. 
     
     
         13 . The resist of  claim 1  wherein said resist comprises additives to improve resolution and line edge roughness. 
     
     
         14 . The resist of  claim 13  wherein said additives comprise bases to quench photo-generated acids. 
     
     
         15 . The resist of  claim 1  wherein said chemical species changes said solubility in the presence of a developer. 
     
     
         16 . The resist of  claim 1  further including responding to plural illuminations separated in time. 
     
     
         17 . The resist of  claim 1  wherein said resist is for use in immersion lithography. 
     
     
         18 . A method of exposing a resist comprising:
 illuminating at least part of said resist with a light source;   inducing, in said resist in a manner that is quadratically dependent on the intensity of said illuminating light, at least one chemical species production based on at least one plural-step reaction; and   changing the solubility of said resist with said chemical species production.   
     
     
         19 . The method of  claim 18  wherein said resist comprises nanocrystal photosensitive material. 
     
     
         20 . The method of  claim 18  wherein said resist comprises semiconductor photosensitive material. 
     
     
         21 . The method of  claim 18  wherein said resist comprises at least one organic molecule photosensitive material. 
     
     
         22 . The method of  claim 18  wherein said resist comprises at least one inorganic molecule photosensitive material. 
     
     
         23 . The method of  claim 18  wherein said resist may comprise an acid quencher. 
     
     
         24 . The method of  claim 18  further including generating an acid in said resist in response to said illuminating. 
     
     
         25 . The method of  claim 24  wherein the acid generation forms an acid in a manner that is quadratically dependent on the intensity of light. 
     
     
         26 . The method of  claim 18  wherein said changing comprises changing the solubility of said resist by chain-scission induced by light through at least one plural-step reaction, said chain-scission being quadratically dependent on the intensity of light. 
     
     
         27 . The method of  claim 18  wherein said changing comprises changing the solubility of said resist by cross-linking induced by light through at least one plural-step reaction, said cross-linking being quadratically dependent on the intensity of light. 
     
     
         28 . The method of  claim 18  wherein said plural-step reaction comprises forming intermediate excited states. 
     
     
         29 . The method of  claim 18  wherein said plural-step reaction comprises a first step which forms a first intermediate result and a second step forming a second intermediate result, said second intermediate result individually and/or combined with said first intermediate result leading to said change in solubility. 
     
     
         30 . The method of  claim 18  wherein said illuminating comprises illuminating with at least one of the following light wavelengths: 157 nm, 193 nm, 248 nm, 257 nm, 198 nm, 121 nm and 365 nm. 
     
     
         31 . The method of  claim 18  wherein said illuminating comprises illuminating with 13.4 nm light. 
     
     
         32 . The method of  claim 18  wherein said changing comprises changing solubility in the presence of a developer. 
     
     
         33 . The method of  claim 18  wherein said illuminating comprises illuminating said resist for a first time period, waiting, and then further illuminating said resist for a second time period. 
     
     
         34 . The method of  claim 18  wherein said illuminating comprises illuminating said resist multiple times separated by waiting times therebetween. 
     
     
         35 . The method of  claim 18  further including exposing said resist using immersion lithography. 
     
     
         36 . A method of manufacturing an article comprising:
 disposing a resist on a substrate;   illuminating at least part of said resist with a light source;   inducing, in said resist in a manner that is quadratically dependent on the intensity of said illuminating light, at least one chemical species production based on at least one plural-step reaction;   changing the solubility of said resist with said chemical species production; and   further processing said changed-solubility resist to fabricate at least one structure on said substrate.   
     
     
         37 . An integrated circuit comprising:
 a substrate; and   at least one structure disposed on said substrate, said at least one structure being formed at least in part by illuminating at least part of said resist with a light source; inducing, in said resist in a manner that is quadratically dependent on the intensity of said illuminating light, at least one chemical species production based on at least one plural-step reaction; changing the solubility of said resist with said chemical species production; and further processing said changed-solubility resist.   
     
     
         38 . An optical device comprising:
 a substrate; and   at least one optical structure disposed on said substrate, said at least one optical structure being formed at least in part by illuminating at least part of said resist with a light source; inducing, in said resist in a manner that is quadratically dependent on the intensity of said illuminating light, at least one chemical species production based on at least one plural-step reaction; changing the solubility of said resist with said chemical species production; and further processing said changed-solubility resist.