Method of improving planarization of urethane polishing pads, and urethane polishing pad produced by the same

Abstract

For improving planarization of urethane polishing pads, at least one layer of the pad has a base resin and an isocyanate with a concentration within a range of 6.5-11.0 weight percent to obtain a high planarization property.

1 . A method of improving planarization of urethane polishing pads, comprising the steps of producing at least one of urethane with a base resin; introducing in the base resin isocyanate; and selecting a concentration of the isocyanate within a range of 6.5-11.0% to obtain a high planarization property.  
     
     
         2 . A method as defined in  claim 1 , wherein selecting includes selecting a concentration of the isocyanate within a range 6.5-8.5%.  
     
     
         3 . A method as defined in  claim 1 , wherein said selecting includes selecting a concentration of the isocyanate within a range of 8.5-11.0%.  
     
     
         4 . A method as defined in  claim 1 , wherein said layer is composed of a polyurethane selected from the group consisting of a polyether polyurethane and polyester polyurethane.  
     
     
         5 . A method as defined in  claim 1 , and further comprising introducing in the layer abrasive particles selected from the group consisting of silica, alumina, ceria, titania, diamond and silicon carbide.  
     
     
         6 . A method as defined in  claim 1 , wherein said producing includes producing the at least one layer without abrasive particles.  
     
     
         7 . A method as defined in  claim 1;  and further comprising introducing a filler into the at least one layer.  
     
     
         8 . A urethane polishing pad, comprising at least one layer having a base resin, and isocyanate introduced in the base resin, wherein a concentration of the isocyanate is within a range of 6.5-11.0%.  
     
     
         9 . A urethane polishing pad as defined in  claim 8 , wherein the concentration of the isocyanate is within a range of 6.5-8.5%.  
     
     
         10 . A urethane polishing pad as defined in  claim 8 , wherein the concentration of the isocyanate is within a range of 8.5-11.0%.  
     
     
         11 . A urethane polishing pad as defined in  claim 8 , wherein at least one layer is composed of polyurethane selected from the group consisting of a polyether polyurethane and polyester polyurethane.  
     
     
         12 . A urethane polishing pad as defined in  claim 8 , wherein said at least one layer contains abrasive particles selected from the group consisting of silica, alumina, ceria, titania, diamond, and silicon carbide.  
     
     
         13 . A urethane polishing pad as defined in  claim 8 , wherein at least one layer is absent of abrasive particles.  
     
     
         14 . A urethane polishing pad as defined in  claim 8 , wherein said at least one layer includes a filler.