Chemical structures and compositions of ECP additives to reduce pit defects

Abstract

A composition and method which is suitable to enhance the wetting of an electroplating bath solution on an electroplating surface. Optimum wetting of the electroplating bath solution to the electroplating surface results in an electroplated metal which is substantially devoid of surface pits and other structural defects and is characterized by enhanced gap fill capability. The composition includes a suppressor additive for the electroplating bath solution. The suppressor additive is a copolymer which includes various proportions of ethylene oxide monomer and propylene oxide monomer.

1 . An electrolyte for copper electroplating, comprising: 
 an electrolyte solution; and    a copolymer comprising ethylene oxide and propylene oxide providing in said electrolyte solution.    
     
     
         2 . The electrolyte of  claim 1  wherein said copolymer is a block copolymer.  
     
     
         3 . The electrolyte of  claim 1  wherein said ethylene oxide is present in said copolymer in a quantity of at least about 60% by weight.  
     
     
         4 . The electrolyte of  claim 1  wherein said copolymer is present in said electrolyte solution in a concentration of from about 50 ppm to about 500 ppm.  
     
     
         5 . The electrolyte of  claim 1  wherein said copolymer is a random copolymer.  
     
     
         6 . The electrolyte of  claim 5  wherein said ethylene oxide is present in said copolymer in a quantity of at least about 60% by weight.  
     
     
         7 . The electrolyte of  claim 1  wherein said copolymer is an alternating copolymer.  
     
     
         8 . The electrolyte of  claim 7  wherein said ethylene oxide is present in said copolymer in a quantity of at least about 60% by weight.  
     
     
         9 . The electrolyte of  claim 1  wherein said ethylene oxide is present in said copolymer in a quantity of about 80% by weight and said propylene oxide is present in said copolymer in a quantity of about 20% by weight.  
     
     
         10 . The electrolyte of  claim 9  wherein said copolymer is a block copolymer.  
     
     
         11 . The electrolyte of  claim 9  wherein said copolymer is a random copolymer.  
     
     
         12 . The electrolyte of  claim 9  wherein said copolymer is an alternating copolymer.  
     
     
         13 . An electrolyte for copper electroplating, comprising: 
 an electrolyte solution;    a copolymer comprising ethylene oxide and propylene oxide providing in said electrolyte solution; and    a leveling agent provided in said electrolyte solution.    
     
     
         14 . The electrolyte of  claim 13  wherein said copolymer is a block copolymer, a random copolymer or an alternating copolymer.  
     
     
         15 . The electrolyte of  claim 13  wherein said ethylene oxide is present in said copolymer in a quantity of at least about 60% by weight.  
     
     
         16 . The electrolyte of  claim 13  wherein said copolymer is present in said electrolyte solution in a concentration of from about 50 ppm to about 500 ppm.  
     
     
         17 . A method of electroplating a metal on an electroplating surface, comprising the steps of: 
 providing an electroplating bath solution;    mixing a copolymer comprising ethylene oxide and propylene oxide with said solution in a concentration of from about 50 ppm to about 500 ppm;    immersing said electroplating surface in said solution; and    electroplating said metal onto said electroplating surface.    
     
     
         18 . The method of  claim 17  wherein said copolymer is a block copolymer, a random copolymer or an alternating copolymer.  
     
     
         19 . The method of  claim 17  wherein said ethylene oxide is present in said copolymer in a quantity of at least about 60% by weight.  
     
     
         20 . The method of  claim 17  wherein said ethylene oxide is present in said copolymer in a quantity of about 80% by weight and said propylene oxide is present in said copolymer in a quantity of about 20% by weight.