Acid generators and photoresists comprising same

Abstract

Acid generator compounds are provided that are particularly useful as a photoresist composition component. In one preferred aspect, photoresists are provided that comprise (i) a polymer; (ii) a first onium salt acid generator that produces a first acid upon exposure of the photoresist composition to activating radiation; and (iii) a second onium salt acid generator that 1) comprises a covalently bound acid-labile moiety and 2) produces a second acid upon exposure of the photoresist composition to activating radiation, wherein the first acid and second acid have pKa values that differ by at least 0.5.

1 . A photoresist composition, comprising:
 (i) a polymer;   (ii) a first onium salt acid generator that produces a first acid upon exposure of the photoresist composition to activating radiation; and   (iii) a second onium salt acid generator that 1) comprises a covalently bound acid-labile moiety and 2) produces a second acid upon exposure of the photoresist composition to activating radiation;   wherein the first acid and second acid have pKa values that differ by at least 0.5.   
     
     
         2 . The photoresist composition of  claim 1  wherein the pKa value of the first acid is lower than the pKa value of the second acid. 
     
     
         3 . The photoresist composition of  claim 1  wherein the pKa value of the second acid is lower than the pKa value of the first acid. 
     
     
         4 . A photoresist composition, comprising:
 (i) a polymer;   (ii) an acid generator that corresponds to the following Formula (I):   
       
         
           
           
               
               
           
         
         wherein R 1 , R 2  and R 3  are the same or different non-hydrogen substituents and any of R 1 , R 2  and R 3  may be taken together to form a ring, and Z is a sulfonate anion with at least one electron withdrawing substituent in the at position of the sulfonate moiety; and 
         (iii) an acid generator that corresponds to the following Formula (II): 
       
       
         
           
           
               
               
           
         
         wherein R 4  and R 5  are the same or different non-hydrogen substituents and may be taken together to form a ring; or either R 4  or R 5  may form a ring with the aromatic substituent; A is a hydrogen or non-hydrogen substituent; m is an integer from 0 to 4; T is a non-hydrogen substituent that provides an acid-labile moiety; and Q is a carboxylate, sulfonate, or sulfamate anion that does not contain an electron withdrawing group in the α position to the carboxylate, sulfonate, or sulfamate moiety. 
       
     
     
         5 . The photoresist composition of  claim 4  wherein the acid generator of Formula (I) corresponds to the following Formula (III): 
       
         
           
           
               
               
           
         
         wherein R 2  and R 3  are the same or different non-hydrogen substituents and may be taken together to form a ring; or either R 2  or R 3  may form a ring with the aromatic substituent; A′″ is a non-hydrogen substituent; m is an integer from 0 to 4; T is a non-hydrogen substituent that provides an acid-labile moiety; and Z is a sulfonate anion with at least one electron withdrawing substituent in the α position of the sulfonate. 
       
     
     
         6 . The photoresist composition of  claim 4  wherein the acid generator of Formula (II) corresponds to the following Formula (IV): 
       
         
           
           
               
               
           
         
         wherein R 4  and R 5  are the same or different non-hydrogen substituents and may be taken together to form a ring; or either R 4  or R 5  may form a ring with the aromatic substituent; A is a non-hydrogen substituent; m is an integer from 0 to 4; R 6  is a non-hydrogen substituent that provides an acid-labile moiety; and Q is a carboxylate, sulfonate, or sulfamate anion that does not contain an electron withdrawing group in the at position to the carboxylate, sulfonate, or sulfamate moiety. 
       
     
     
         7 . The photoresist composition of  claim 4  wherein Z is bound to the polymer. 
     
     
         8 . The photoresist composition of  claim 4  wherein the acid generator of either or both of Formulae (I), (II), (III), and (IV) contains either a thioxanthone or dibenzothiophene moiety. 
     
     
         9 . A method for providing a photoresist relief image, comprising:
 a) applying a coating layer of a photoresist composition of  claim 1  on a substrate; and   b) exposing the photoresist composition layer to activating radiation and developing the exposed photoresist composition coating layer.   
     
     
         10 . The method of  claim 9  wherein the photoresist composition layer is exposed to EUV or e-beam radiation.