Polishing Composition and Polishing Method

Abstract

A polishing composition contains at least one water soluble polymer selected from the group consisting of polyvinylpyrrolidone and poly(N-vinylformamide), and an alkali, and preferably further contains at least one of a chelating agent and an abrasive grain. The water soluble polymer preferably has a weight average molecular weight of 6,000 to 4,000,000. The polishing composition is mainly used in polishing of the surfaces of semiconductor wafers such as silicon wafers, especially used in preliminary polishing of the surfaces of such wafers.

1 .- 5 . (canceled) 
   
   
       6 . A method of polishing, comprising polishing a surface of a semiconductor wafer using a polishing composition containing a water soluble polymer comprising poly(N-vinylformamide), abrasive grains, and an alkali. 
   
   
       7 . The method according to  claim 6 , wherein said polishing includes preliminary polishing a surface of a semiconductor wafer using said polishing composition and finish polishing a preliminary polished surface of the semiconductor using a polishing composition different from said polishing composition. 
   
   
       8 . A method of polishing, comprising polishing a surface of a silicon wafer using a polishing composition containing a water soluble polymer comprising polyvinylpyrrolidone, and an alkali. 
   
   
       9 . The method according to  claim 8 , wherein said polishing includes preliminary polishing a surface of a silicon wafer using said polishing composition and finish polishing a preliminary polished surface of the silicon wafer using a polishing composition different from said polishing composition. 
   
   
       10 . The method according to  claim 8 , wherein the water soluble polymer has a weight average molecular weight of 6,000 to 4,000,000. 
   
   
       11 . The method according to  claim 8 , further comprising a chelating agent. 
   
   
       12 . The method according to  claim 8 , further comprising at least one abrasive grain selected from the group consisting of colloidal silica and fumed silica. 
   
   
       13 . The method according to  claim 11 , further comprising at least one abrasive grain selected from the group consisting of colloidal silica and fumed silica. 
   
   
       14 . The method according to  claim 11 , wherein the chelating agent is an aminocarboxylic acid-based chelating agent. 
   
   
       15 . The method according to  claim 11 , wherein the chelating agent is a phosphonic acid-based chelating agent. 
   
   
       16 . The method according to  claim 8 , wherein the water soluble polymer is contained in the polishing composition in an amount of 0.0003 to 0.1 g/L. 
   
   
       17 . The method according to  claim 16 , wherein the water soluble polymer is contained in the polishing composition in an amount of 0.005 to 0.01 g/L. 
   
   
       18 . The method according to  claim 8 , wherein the alkali is contained in the polishing composition in an amount of 0.1 to 5 g/L. 
   
   
       19 . The method according to  claim 18 , wherein the alkali is contained in the polishing composition in an amount of 0.5 to 3 g/L. 
   
   
       20 . A method of polishing, comprising:
 preparing a polishing composition containing:
 polyvinylpyrrolidone of a content in a range of from 0.005 to 0.01 g/L in the polishing composition; 
 an alkali of a content in a range of from 0.5 to 3 g/L; 
 a chelating agent of a content of about 0.3 g/L; 
 colloidal silica or fumed silica of a content in a range of 5 to 25 g/L; and 
 water; and 
   polishing a surface of a silicon wafer using the polishing composition, wherein said polishing includes preliminary polishing a surface of a silicon wafer using said polishing composition and finish polishing a preliminary polished surface of the semiconductor silicon wafer using a polishing composition different from said polishing composition.