Anti-reflective coatings and dual damascene fill compositions comprising styrene-allyl alcohol copolymers

Abstract

New anti-reflective or fill compositions having improved flow properties are provided. The compositions comprise a styrene-allyl alcohol polymer and preferably at least one other polymer (e.g., cellulosic polymers) in addition to the styrene-allyl alcohol polymer. The inventive compositions can be used to protect contact or via holes from degradation during subsequent etching in the dual damascene process. The inventive compositions can also be applied to substrates (e.g., silicon wafers) to form anti-reflective coating layers having high etch rates which minimize or prevent reflection during subsequent photoresist exposure and developing.

1. In an anti-reflective or fill composition for protecting a base material or holes formed in a base material, the improvement being that said composition comprises a styrene-allyl alcohol polymer and a polymer selected from the group consisting of cellulose polymers, novolaks, and mixtures thereof, wherein said polymers are dispersed in a solvent system, said solvent system being utilized at a level from about  80 -   98   %  by weight, based on the total weight of composition taken as  100   %  by weight . 
     
     
       2. The composition of  claim 1 , wherein said polymers are dispersed in a  solvent system which  includes a solvent selected from the group consisting of 1-methoxy-2-propanol, PGMEA, PGME, propylene glycol n-propyl ether, 2-heptanone, N-methylpyrollidinone, ethyl lactate, and mixtures thereof. 
     
     
       3. The composition of  claim 1 , wherein said composition comprises from about 1-10% by weight styrene-allyl alcohol polymer, based upon the total weight of the composition taken as 100% by weight. 
     
     
       4. The composition of  claim 1 , wherein said styrene-allyl alcohol polymer comprises from about 40-90% by weight styrene, based upon the total weight of the styrene-allyl alcohol polymer taken as 100% by weight. 
     
     
       5. The composition of  claim 1 , wherein said styrene-allyl alcohol polymer comprises from about 10-60% by weight allyl alcohol, based upon the total weight of the styrene-allyl alcohol polymer taken as 100% by weight. 
     
     
       6. The composition of  claim 1 , wherein the molar ratio of styrene to allyl alcohol is from about 0.4:1 to about 4:1. 
     
     
       7. The composition of  claim 1 , wherein said composition further comprises a compound selected from the group consisting of crosslinking agents, catalysts, light attenuating compounds, and mixtures thereof. 
     
     
       8. The composition of  claim 7 , wherein said compound is an aminoplast crosslinking agent. 
     
     
       9. The composition of  claim 7 , wherein said compound is a catalyst selected from the group consisting of p-toluenesulfonic acid, bisphenol-A, 4,4′-sulfonyldiphenol, pyridinium p-toluenesulfonate, and mixtures thereof. 
     
     
       10. The composition of  claim 1 , wherein said composition comprises from about 0.5-10% by weight of said additional polymer, based upon the total weight of the composition taken as 100% by weight. 
     
     
       11. The composition of  claim 1 , wherein said styrene-allyl alcohol polymer has a weight average molecular weight of from about 1000-10,000 Daltons.