Photoresist compositions comprising diamondoid derivatives

Abstract

Novel positive-working photoresist compositions are disclosed. The monomers of the base resin of the resist contain diamondoid-containing pendant groups higher than adamantane in the polymantane series; for example, diamantane, triamantane, tetramantane, pentamantane, hexamantane, etc. The diamondoid-containing pendant group may have hydrophilic-enhancing substituents such as a hydroxyl group, and may contain a lactone group. Advantages of the present compositions include enhanced resolution, sensitivity, and adhesion to the substrate.

1 . A positive-working photoresist composition comprising a base resin represented by the general formula: 
     
       
         
         
             
             
         
       
       wherein R 1  is selected from the group consisting of —H and —CH 3 ; 
       R 2  is selected from the group consisting of —H, an alkyl group having from 1 to 4 carbon atoms, and an alkoxy group having from 1 to 4 carbon atoms; 
       R 3  is —H, or a hydrophilic-enhancing moiety selected from the group consisting of a hydroxyl group —OH, a keto group ═O, carboxylic acid group —COOH, and alkoxy group —OR 4 , and a group —OC(O)OR 4 ; 
       R 4  is —CH 3  or —C 2 H 5 ; 
       a is 0.25 to 0.75; 
       b+c+d+e is substantially equal to 1−a; with e being greater than 0, and 
       P 1  is a non-diamondoid, acid-cleavable pendant group. 
     
   
   
       2 . The photoresist composition of  claim 1 , wherein c ranges from about 0 to 0.25. 
   
   
       3 . The photoresist composition of  claim 1 , wherein d ranges from about 0 to 0.25. 
   
   
       4 . The photoresist composition of  claim 1 , wherein e is 0.25 or less. 
   
   
       5 . The photoresist composition of  claim 1 , wherein c+d+e is 0.25 or less. 
   
   
       6 . The photoresist composition of  claim 1 , wherein b, the amount of the adamantane containing monomer, is about equal to c+d+e, the total amount of the diamantane, triamantane, and higher diamondoid-containing monomers. 
   
   
       7 . The photoresist composition of  claim 1 , wherein P 1  is a lactone-containing pendant group. 
   
   
       8 . The photoresist composition of  claim 1 , wherein the average Onishi number of any of the diamondoid containing monomers is greater than about 3. 
   
   
       9 . The photoresist composition of  claim 1 , wherein the average value of the solubility parameter of the base resin, in units of cal 0.5 /cm 1.5 , ranges from about 8 to 13. 
   
   
       10 . The photoresist composition of  claim 1 , further including a photoacid generator selected from the group consisting of an onium salt, a diazonium salt, an ammonium salt, a phosphonium salt, an iodonium salt, a sulfonium salt, a selenonium salt, an arsonium salt, an organic halogeno compound, and an organo-metal/organic halide compound. 
   
   
       11 . The photoresist composition of  claim 10 , wherein the photoacid generator has an o-nitorbenzyl type protecting group. 
   
   
       12 . The photoresist composition of  claim 10 , wherein the photoacid generator generates a sulfonic acid upon photolysis. 
   
   
       13 . The photoresist composition of  claim 10 , wherein the amount of the photoacid generator in the composition ranges from about 0.01 to 30 weight percent. 
   
   
       14 . The photoresist composition of  claim 1 , wherein the composition further comprises an additive selected from the group consisting of a surface active agent, an organic basic compound, an acid decomposable dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, a compound promoting solubility in a developing solution, and additives comprising hydrophilic diamondoid derivatives. 
   
   
       15 . The photoresist composition of  claim 1 , wherein the composition further includes a solvent selected from the group consisting of ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), ethylene carbonate, toluene, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl methoxypropionate, ethyl pyruvate, propyl pyruvate, N,N-dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, and tetrahydrofuran. 
   
   
       16 . The photoresist composition of  claim 1 , wherein b, c, and d are 0.