Polishing pad and chemical mechanical polishing method

Abstract

A polishing pad for chemical mechanical polishing, which has an excellent removal rate and is capable of polishing for providing excellent planarity. This polishing pad comprises 70 to 99.9 mass % of (A) a crosslinked diene elastomer and 0.1 to 30 mass % of (B) a polymer having an acid anhydride structure based on 100 mass % of the total of the above components (A) and (B) and has a specific gravity of 0.9 to 1.2.

What is claimed is:  
     
         1 . A polishing pad comprising 70 to 99.9 mass % of (A) a crosslinked diene elastomer and 0.1 to 30 mass % of (B) a polymer having an acid anhydride structure based on 100 mass % of the total of the components (A) and (B) and having a specific gravity of 0.9 to 1.2.  
     
     
         2 . The polishing pad of  claim 1 , wherein the crosslinked diene elastomer (A) is a crosslinked butadiene elastomer or crosslinked isoprene elastomer.  
     
     
         3 . The polishing pad of  claim 1 , wherein the polymer having an acid anhydride structure (B) is a polymer having an acid anhydride structure only in the main chain, a polymer having an acid anhydride structure only in the side chain or a polymer having an acid anhydride structure in both the main chain and the side chain.  
     
     
         4 . The polishing pad of  claim 3 , wherein the polymer having an acid anhydride structure only in the main chain is a (co)polymer of at least one unsaturated dicarboxylic anhydride selected from the group consisting of maleic anhydride, itaconic anhydride, citraconic anhydride and endomethylenetetrahydrophthalic anhydride, or a copolymer of at least one unsaturated dicarboxylic anhydride and a monomer having no acid anhydride structure.  
     
     
         5 . The polishing pad of  claim 3 , wherein the polymer having an acid anhydride structure only in the side chain is a polymer obtained by modifying a polymer having no acid anhydride structure with at least one unsaturated dicarboxylic anhydride selected from the group consisting of maleic anhydride, itaconic anhydride, citraconic anhydride and endomethylenetetrahydrophthalic anhydride.  
     
     
         6 . The polishing pad of  claim 3  or  5 , wherein the polymer having an acid anhydride structure only in the side chain is maleic anhydride modified polyethylene, maleic anhydride modified polypropylene or maleic anhydride modified styrene-butadiene copolymer.  
     
     
         7 . The polishing pad of  claim 3 , wherein the polymer having an acid anhydride structure in both the main chain and the side chain is a polymer obtained by modifying a polymer having an acid anhydride structure only in the main chain with at least one unsaturated dicarboxylic anhydride selected from the group consisting of maleic anhydride, itaconic anhydride, citraconic anhydride and endomethylenetetrahydrophthalic anhydride.  
     
     
         8 . The polishing pad of  claim 1 , wherein the acid value of the polymer having an acid anhydride structure (B) is 0.1 to 500 mg KOH/g.  
     
     
         9 . The polishing pad of  claim 1 , wherein the crosslinked diene elastomer (A) and the polymer having an acid anhydride structure (B) form a matrix material and a water-soluble substance (C) is further contained in the matrix material.  
     
     
         10 . A chemical mechanical polishing method comprising flattening the surface of a material to be polished by chemical mechanical polishing with the polishing pad of  claim 1.