CMP pad with long user life

Abstract

Chemical mechanical polishing (“CMP”) systems utilize specially designed pads to precision polish ultra-flat surfaces of silicon wafers and other similar materials. This invention proposes improving the longevity and performance of CMP pads by modifying the surface properties of the pads through treatment of the surface with radiation or through the inclusion of metals or metal oxides in the surface layer of the pad.

1 . A CMP pad comprising an outermost layer that differs from the rest of pad beneath said outermost layer.  
     
     
         2 . A CMP pad of  claim 1 , wherein said pad is made of polyurethane or polyurethane composites.  
     
     
         3 . A CMP pad of  claim 1 , wherein the thickness of said outermost layer is at least 0.05 micron.  
     
     
         4 . A CMP pad according to  claim 1 , wherein said outermost layer is produced by subjecting the surface of the finished, as manufactured pad to electromagnetic radiation, selected from the group of EB, UV and IR.  
     
     
         5 . A CMP pad according to  claim 4 , wherein the bulk material of the pad comprises radiation-sensitive compounds.  
     
     
         6 . A CMP pad according to  claim 1 , wherein said outermost layer is produced by applying a layer or film onto the pad, such layer or film being designed to improve its CMP performance.  
     
     
         7 . A CMP pad according to  claim 6 , wherein said layer is sensitive to heat or radiation.  
     
     
         8 . A CMP pad according to  claim 6 , wherein said outermost layer is made of a metal, metal oxide, metal alloy, or metal comprising compound, capable to reduce galvanic attack of copper interconnects.  
     
     
         9 . A CMP pad according to  claim 8 , wherein said outermost layer is made of Cu 2 O, CuO, finely devided Cu metal powder, SnO, SnO 2 , finely divided tin metal and combinations thereof.  
     
     
         10 . A CMP pad according to  claim 1  being a slurry-delivering pad.  
     
     
         11 . A CMP pad according to  claim 1 , being a fixed abrasive pad.