Anti-reflective coatings using vinyl ether crosslinkers

Abstract

Novel, wet developable anti-reflective coating compositions and methods of using those compositions are provided. The compositions comprise a polymer and/or oligomer having acid functional groups and dissolved in a solvent system along with a crosslinker and a photoacid generator. The preferred acid functional group is a carboxylic acid, while the preferred crosslinker is a vinyl ether crosslinker. In use, the compositions are applied to a substrate and thermally crosslinked. Upon exposure to light, the cured compositions will decrosslink, rendering them soluble in typical photoresist developing solutions (e.g., alkaline developers).

1 . A composition useful for forming microelectronic devices, said composition comprising: 
 a compound selected from the group consisting of polymers, oligomers, and mixtures thereof, said compound comprising an acid group other than a phenolic group;    a vinyl ether crosslinker; and    a solvent system, said compound and crosslinker being dissolved or dispersed in said solvent system,    said composition being wet developable.    
   
   
       2 . The composition of  claim 1 , said composition further comprising an acid generator.  
   
   
       3 . The composition of  claim 2 , wherein said acid generator is a photoacid generator.  
   
   
       4 . The composition of  claim 1 , wherein said compound is not acid-sensitive.  
   
   
       5 . The composition of  claim 1 , wherein said acid group is free of protective groups.  
   
   
       6 . The composition of  claim 1 , wherein said compound comprises protected acid groups and unprotected acid groups, and the molar ratio of protected acid groups to unprotected acid groups is from about 1:3 to about 3:1.  
   
   
       7 . The composition of  claim 1 , wherein said composition further comprises a chromophore.  
   
   
       8 . The composition of  claim 7 , wherein said chromophore is bonded with said compound.  
   
   
       9 . The composition of  claim 7 , wherein said chromophore is present in said composition at a level of from about 5-50% by weight, based upon the total weight of the compound taken as 100% by weight.  
   
   
       10 . The composition of  claim 1 , wherein said vinyl ether crosslinker has the formula R—(X—O—CH═CH 2 ) n , where: 
 R is selected from the group consisting of aryls and alkyls;    each X is individually selected from the group consisting of alkyls, alkoxys, carboxys, and combinations of two or more thereof; and    n is 2-6.    
   
   
       11 . The composition of  claim 10 , wherein said vinyl ether crosslinker is selected from the group consisting of ethylene glycol vinyl ether, trimethylolpropane trivinyl ether, 1,4-cyclohexane dimethanol divinyl ether,  
     
       
         
         
             
             
         
       
     
     and mixtures thereof.  
   
   
       12 . The composition of  claim 1 , wherein said acid group is a carboxylic acid.  
   
   
       13 . The composition of  claim 1 , wherein said polymer is selected from the group consisting of aliphatic polymers, acrylates, methacrylates polyesters, polycarbonates, novolaks, polyamic acids, and mixtures thereof.  
   
   
       14 . A method of forming a microelectronic structure, said method comprising the steps of: 
 providing a substrate having a surface;    applying a composition to said surface, said composition comprising: 
 a compound selected from the group consisting of polymers, oligomers, and mixtures thereof, said compound comprising an acid group other than a phenolic group;  
 a vinyl ether crosslinker; and  
 a solvent system, said compound and crosslinker being dissolved or dispersed in said solvent system,  
   crosslinking the compound in said composition;    exposing said composition to light to yield an exposed portion of said composition; and    contacting said composition with a developer so as to remove said exposed portion from said surface.    
   
   
       15 . The method of  claim 14 , wherein said crosslinking step comprises thermally crosslinking said compound.  
   
   
       16 . The method of  claim 14 , wherein said crosslinking step yields a layer of composition that is substantially insoluble in photoresist solvents.  
   
   
       17 . The method of  claim 16 , wherein said crosslinking step yields crosslinked compounds comprising linkages having the formula  
     
       
         
         
             
             
         
       
     
   
   
       18 . The method of  claim 14 , where said exposing step yields a layer of composition that is substantially soluble in photoresist developers.  
   
   
       19 . The method of  claim 17 , wherein said exposing step results in the breaking of the bond (*) of the linkage having the formula  
     
       
         
         
             
             
         
       
     
   
   
       20 . The method of  claim 14 , wherein said substrate is a microelectronic substrate.  
   
   
       21 . The method of  claim 20 , wherein said substrate is selected from the group consisting of silicon, aluminum, tungsten, tungsten silicide, gallium arsenide, germanium, tantalum, tantalum nitrite, SiGe, ion implant layers, low k dielectric layers, and dielectric layers.  
   
   
       22 . The method of  claim 14 , wherein: 
 said substrate further comprises structure defining a hole, said structure including sidewalls and a bottom wall; and    said applying step comprises applying the composition to at least a portion of said hole sidewalls and bottom wall.    
   
   
       23 . The method of  claim 14 , wherein said substrate comprises an ion implant layer, and said applying step comprises forming a layer of said composition adjacent said ion implant layer.  
   
   
       24 . The method of  claim 14 , further comprising the step of applying a photoresist layer prior to said exposing step.  
   
   
       25 . A method of forming a microelectronic structure, said method comprising the steps of: 
 providing a substrate having a surface;    applying a composition to said surface, said composition comprising a compound dissolved or dispersed in a solvent system, said compound being selected from the group consisting of polymers, oligomers, and mixtures thereof, said compound comprising a carboxylic acid group;    crosslinking the compound in said composition; and    exposing said composition to light so as to decrosslink said compound.    
   
   
       26 . The method of  claim 25 , wherein said crosslinking step comprises thermally crosslinking said compound.  
   
   
       27 . The method of  claim 25 , wherein said crosslinking step yields a layer of composition that is substantially insoluble in photoresist solvents.  
   
   
       28 . The method of  claim 25 , wherein crosslinking step yields crosslinked compounds comprising linkages having the formula  
     
       
         
         
             
             
         
       
     
   
   
       29 . The method of  claim 25 , where said exposing step yields a layer of composition that is substantially soluble in photoresist developers.  
   
   
       30 . The method of  claim 28 , wherein said exposing step results in the breaking of the bond (*) of the linkage having the formula  
     
       
         
         
             
             
         
       
     
   
   
       31 . The method of  claim 25 , wherein said substrate is a microelectronic substrate.  
   
   
       32 . The method of  claim 31 , wherein said substrate is selected from the group consisting of silicon, aluminum, tungsten, tungsten silicide, gallium arsenide, germanium, tantalum, tantalum nitrite, SiGe, ion implant layers, low k dielectric layers, and dielectric layers.  
   
   
       33 . The method of  claim 25 , wherein: 
 said substrate further comprises structure defining a hole, said structure including sidewalls and a bottom wall; and    said applying step comprises applying the composition to at least a portion of said hole sidewalls and bottom wall.    
   
   
       34 . The method of  claim 25 , wherein said substrate comprises an ion implant layer, and said applying step comprises forming a layer of said composition adjacent said ion implant layer.  
   
   
       35 . The method of  claim 25 , further comprising the step of applying a photoresist layer prior to said exposing step.  
   
   
       36 . The combination of: 
 a substrate; and    a layer adjacent said substrate, said layer comprising a crosslinked compound comprising linkages having the formula                          
   
   
       37 . The combination of  claim 36 , wherein said substrate is amicroelectronic substrate.  
   
   
       38 . The combination of  claim 37 , wherein said substrate is selected from the group consisting of silicon, aluminum, tungsten, tungsten silicide, gallium arsenide, germanium, tantalum, tantalum nitrite, SiGe, ion implant layers, low k dielectric layers, and dielectric layers.  
   
   
       39 . The combination of  claim 36 , wherein said layer is substantially insoluble in photoresist solvents.  
   
   
       40 . The combination of  claim 36 , further comprising a photoresist adjacent said layer.  
   
   
       41 . The combination of: 
 a substrate; and    a layer adjacent said substrate, said layer comprising a mixture of: 
 a compound selected from the group consisting of polymers, oligomers, and mixtures thereof, said compound comprising an acid group;  
 an alcohol; and  
 acetylaldehyde.  
   
   
   
       42 . The combination of  claim 41 , wherein said substrate is a microelectronic substrate.  
   
   
       43 . The combination of  claim 42 , wherein said substrate is selected from the group consisting of silicon, aluminum, tungsten, tungsten silicide, gallium arsenide, germanium, tantalum, tantalum nitrite, SiGe, ion implant layers, low k dielectric layers, and dielectric layers.  
   
   
       44 . The combination of  claim 41 , wherein said layer is substantially soluble in photoresist developers.  
   
   
       45 . The combination of  claim 41 , further comprising a photoresist adjacent said layer.  
   
   
       46 . A compound having the formula