Release agent partition control in imprint lithography

Abstract

Release agents with increased affinity toward nano-imprint lithography template surfaces interact strongly with the template during separation of the template from the solidified resist in a nano-imprint lithography process. The strong interaction between the surfactant and the template surface reduces the amount of surfactant pulled off the template surface during separation of a patterned layer from the template in an imprint lithography cycle. Maintaining more surfactant associated with the surface of the template after the separation of the patterned layer from the template may reduce the amount of surfactant needed in a liquid resist to achieve suitable release of the solidified resist from the template during an imprint lithography process. Strong association of the release agent with the surface of the template facilitates the formation of ultra-thin residual layers and dense fine features in nano-imprint lithography.

1 . An imprint lithography release agent comprising:
 a non-polar fluorinated portion; and   a polar poly(oxyalkylene) portion bonded to the non-polar fluorinated portion, the polar poly(oxyalkylene) portion formed from a multiplicity of oxyalkylene units, the multiplicity comprising at least one ethylene oxide unit,   wherein the release agent is capable of forming multiple polar interactions with a surface of an imprint lithography template.   
     
     
         2 . The imprint lithography release agent of  claim 1 , wherein the polar poly(oxyalkylene) portion is formed from a multiplicity of oxyalkylene units including at least three ethylene oxide units. 
     
     
         3 . The imprint lithography release agent of  claim 1 , wherein the polar poly(oxyalkylene) portion is formed from a multiplicity of oxyalkylene units including at least ten ethylene oxide units. 
     
     
         4 . The imprint lithography release agent of  claim 1 , wherein the polar poly(oxyalkylene) portion is formed from a multiplicity of oxyalkylene units including at least one propylene oxide unit. 
     
     
         5 . The imprint lithography release agent of  claim 1 , wherein the fluorinated portion comprises a perfluorinated polyether portion. 
     
     
         6 . The imprint lithography release agent of  claim 1 , wherein the release agent further comprises a nitrogen atom, wherein the nitrogen atom is capable of forming a polar interaction with the surface of the imprint lithography template. 
     
     
         7 . The imprint lithography release agent of  claim 1 , wherein the release agent further comprises two or more nitrogen atoms wherein the nitrogen atoms are capable of forming polar interactions with the surface of the imprint lithography template. 
     
     
         8 . The imprint lithography release agent of  claim 1 , wherein the release agent further comprises an atom capable of forming a covalent bond with the surface of the imprint lithography template, wherein a strength of the covalent bond is less than the strength of a silicon-oxygen bond at the surface of the template. 
     
     
         9 . The imprint lithography release agent of  claim 8 , wherein the release agent further comprises a boron atom, and wherein the boron atom is capable of forming a covalent bond with the surface of the imprint lithography template. 
     
     
         10 . The imprint lithography release agent of  claim 1 , wherein the release agent is liquid at room temperature. 
     
     
         11 . The imprint lithography release agent of  claim 1 , the release agent having the chemical structure 
       
         
           
           
               
               
           
         
       
       wherein each R a  is independently H 3 C[OCH 2 CH 2 ] x [OCH 2 CHCH 3 ] y —, and m and n and x and y are integers. 
     
     
         12 . The imprint lithography release agent of  claim 1 , the release agent comprising polar groups capable of forming a cyclic hydrogen bonding interaction with the surface of the template. 
     
     
         13 . The imprint lithography release agent of  claim 1 , the release agent further comprising two or more hydroxyl groups capable of forming polar interactions with the surface of the template. 
     
     
         14 . The imprint lithography release agent of  claim 1 , the release agent further comprising a carboxyl group capable of forming polar interactions with the surface of the template. 
     
     
         15 . The imprint lithography release agent of  claim 1 , the release agent further comprising a pyridazinyl group capable of forming polar interactions with the surface of the template. 
     
     
         16 . The imprint lithography release agent of  claim 1 , wherein the release agent is non-ionic. 
     
     
         17 . An imprint lithography mold assembly comprising:
 an imprint lithography substrate;   a polymerizable material disposed on the substrate; and   an imprint lithography template having a surface, the surface in contact with the polymerizable material,   wherein the polymerizable material comprises an imprint lithography release agent comprising:
 a non-polar fluorinated portion; and 
 a polar poly(oxyalkylene) portion bonded to the non-polar fluorinated portion, the polar poly(oxyalkylene) portion formed from a multiplicity of oxyalkylene units, the multiplicity comprising at least one ethylene oxide unit, and 
   wherein the release agent is associated with the surface of the template through multiple polar interactions.   
     
     
         18 . The imprint lithography mold assembly of  claim 17 , wherein the release agent forms a lamella layer at the surface of the imprint lithography template. 
     
     
         19 . The imprint lithography mold assembly of  claim 17 , wherein the polymerizable material further comprises a compound including a perfluorinated polyether portion and an acrylate group. 
     
     
         20 . The imprint lithography mold assembly of  claim 17 , wherein the polymerizable material further comprises a compound including a perfluorinated polyether portion and two acrylate groups. 
     
     
         21 . A imprint lithography liquid resist comprising:
 a monomer;   a cross-linking agent;   a photoinitiator;   a catalyst; and   a release agent comprising:
 a non-polar fluorinated portion; and 
 a polar poly(oxyalkylene) portion bonded to the non-polar fluorinated portion, the polar poly(oxyalkylene) portion formed from a multiplicity of oxyalkylene units including at least one ethylene oxide unit. 
   
     
     
         22 . The liquid resist of  claim 21 , wherein the fluorinated portion of the release agent comprises a perfluorinated polyether. 
     
     
         23 . The liquid resist of  claim 21 , further comprising a compound comprising a perfluorinated polyether group and one or more acrylate groups. 
     
     
         24 . A imprint lithography method comprising:
 disposing a polymerizable composition on an imprint lithography substrate;   contacting the polymerizable composition with an imprint lithography template;   solidifying the polymerizable composition to form a patterned layer adhered to the imprint lithography substrate; and   separating the imprint lithography template from the solidified patterned layer,   wherein the polymerizable composition comprises an imprint lithography release agent, the release agent comprising:
 a non-polar fluorinated portion; and 
 a polar poly(oxyalkylene) portion bonded to the non-polar fluorinated portion, the polar poly(oxyalkylene) portion formed from a multiplicity of oxyalkylene units including at least one ethylene oxide unit, 
   wherein contacting the polymerizable composition with the imprint lithography template comprises forming multiple polar interactions between the release agent and the surface of the imprint lithography template.   
     
     
         25 . The imprint lithography method of  claim 24 , wherein separating the imprint lithography template from the solidified patterned layer comprises breaking less than about half of the polar interactions between the release agent and the surface of the imprint lithography template. 
     
     
         26 . A method of forming an imprint lithography template, the method comprising:
 cleaning an imprint lithography template to form hydroxyl groups on the surface of the template;   introducing a metal-containing compound to react with the surface hydroxyl groups;   introducing water vapor to form metal-OH on the surface of the template; and   annealing the metal-OH to form a layer of metal oxide on the surface of the imprint lithography template, wherein the surface of the template is capable of forming ionic and polar interactions with an imprint lithography release agent.   
     
     
         27 . The method of  claim 26 , wherein the metal-containing compound is Al(CH 3 ) 3 .