Chemical mechanical polishing method

Abstract

A chemical mechanical polishing method, including: chemically and mechanically polishing a polishing target surface by continuously performing a first polishing step and a second polishing step having a polishing rate lower than a polishing rate of the first polishing step, a chemical mechanical polishing aqueous dispersion used in the first polishing step and the second polishing step being a mixture of an aqueous dispersion and an aqueous solution, and the polishing rate being changed between the first polishing step and the second polishing step by changing a mixing ratio of the aqueous dispersion and the aqueous solution.

1 . A chemical mechanical polishing method, comprising:
 chemically and mechanically polishing a polishing target surface comprising copper by continuously performing a first polishing step and a second polishing step having a polishing rate lower than a polishing rate of the first polishing step, a chemical mechanical polishing aqueous dispersion used in the first polishing step and the second polishing step being a mixture of an aqueous dispersion (I) and an aqueous solution (II), and the polishing rate being changed between the first polishing step and the second polishing step by changing a mixing ratio of the aqueous dispersion (I) and the aqueous solution (II), wherein the polishing rate of the second step is 10 to 90% of the polishing rate of the first steps   wherein:   the aqueous dispersion (I) comprises (A) abrasives,   the aqueous solution (II) comprises at least one selected from the group consisting of (B) quinolinic acid, (C) a polishing rate improver, and (D) an oxidizing agent,   the pH of the aqueous dispersion (I) is from 7 to 12 and   the pH of the aqueous solution (II) is from 3 to 12.   
   
   
       2 . A chemical mechanical polishing method, comprising:
 chemically and mechanically polishing a polishing target surface comprising copper by continuously performing a first polishing step and a second polishing step having a polishing rate lower than a polishing rate of the first polishing step, a chemical mechanical polishing aqueous dispersion used in the first polishing step and the second polishing step being a mixture of an aqueous dispersion (I) and an aqueous solution (II), and the polishing rate being changed between the first polishing step and the second polishing step by changing a mixing ratio of the aqueous dispersion (I) and the aqueous solution (II), wherein the first polishing step is switched to the second polishing step when the thickness of the polishing target is 200 to 700 nm,   wherein:   the aqueous dispersion (I) comprises (A) abrasives,   the aqueous solution (II) comprises at least one selected from the group consisting of (B) quinolinic acid, (C) a polishing rate improver, and (D) an oxidizing agent,   the pH of the aqueous dispersion (I) is from 7 to 12 and   the pH of the aqueous solution (II) is from 3 to 12.   
   
   
       3 . The chemical mechanical polishing method as defined in  claim 1 , wherein the aqueous dispersion (I) further comprises (D) an oxidizing agent. 
   
   
       4 . The chemical mechanical polishing method as defined in  claim 2 , wherein the aqueous dispersion (I) further comprises (D) an oxidizing agent. 
   
   
       5 . The chemical mechanical polishing method as defined in  claim 1 , wherein the aqueous solution (II) further comprises (D) an oxidizing agent. 
   
   
       6 . The chemical mechanical polishing method as defined in  claim 2 , wherein the aqueous solution (II) further comprises (D) an oxidizing agent. 
   
   
       7 . The chemical mechanical polishing method as defined in  claim 1 , wherein the polishing target surface further comprises an insulating film and wherein the aqueous solution (II) comprises no (A) abrasives. 
   
   
       8 . The chemical mechanical polishing method as defined in  claim 2 , wherein the polishing target surface further comprises an insulating film and wherein the aqueous solution (II) comprises no (A) abrasives. 
   
   
       9 . The chemical mechanical polishing method as defined in  claim 1 , wherein the aqueous dispersion (I) comprises no (C) polishing rate improver. 
   
   
       10 . The chemical mechanical polishing method as defined in  claim 2 , wherein the aqueous dispersion (I) comprises no (C) polishing rate improver. 
   
   
       11 . The chemical mechanical polishing method as defined in  claim 1 , wherein the pH of the aqueous dispersion (I) is basic. 
   
   
       12 . The chemical mechanical polishing method as defined in  claim 2 , wherein the pH of the aqueous dispersion (I) is basic.