Aqueous dispersion for chemical mechanical polishing, kit for preparing the aqueous dispersion, chemical mechanical polishing process, and process for producing semiconductor devices

Abstract

An aqueous dispersion for chemical mechanical polishing contains water, a polyvinylpyrrolidone having a weight-average molecular weight exceeding 200,000, an oxidant, a protective film-forming agent and abrasive grains, the protective film-forming agent containing a first metal compound-forming agent which forms a water-insoluble metal compound, and a second metal compound-forming agent which forms a water-soluble metal compound. The aqueous dispersion is capable of uniformly and stably polishing a metal film at low friction without causing defects in a metal film and an insulating film.

1 . An aqueous dispersion for chemical mechanical polishing, comprising water, a polyvinylpyrrolidone having a weight-average molecular weight exceeding 200,000, an oxidant, a protective film-forming agent and abrasive grains, the protective film-forming agent comprising a first metal compound-forming agent which forms a water-insoluble metal compound, and a second metal compound-forming agent which forms a water-soluble metal compound.  
   
   
       2 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , wherein the water-insoluble metal compound is a water-insoluble complex.  
   
   
       3 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , wherein the water-soluble metal compound is a water-soluble complex.  
   
   
       4 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , wherein the polyvinylpyrrolidone has a K value exceeding 57 as determined by the Fikentscher method.  
   
   
       5 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , which has a viscosity of less than 2 mPa·a.  
   
   
       6 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , further comprising a surface active agent.  
   
   
       7 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , wherein the abrasive grains have an average particle size of 5 to 1000 nm.  
   
   
       8 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , wherein the content of the polyvinylpyrrolidone is from 0.001 to 0.5% by weight of the aqueous dispersion.  
   
   
       9 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , wherein the content of the oxidant is from 0.05 to 5% by weight of the aqueous dispersion.  
   
   
       10 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , wherein the content of the protective film-forming agent is from 0.001 to 3.0% by weight of the aqueous dispersion.  
   
   
       11 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , wherein the content of the first metal compound-forming agent is from 0.0005 to 2.0% by weight of the aqueous dispersion.  
   
   
       12 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , wherein the content of the second metal compound-forming agent is from 0.0005 to 2.0% by weight of the aqueous dispersion.  
   
   
       13 . The aqueous dispersion for chemical mechanical polishing according to  claim 1 , wherein the content of the abrasive grains is from 0.01 to 5% by weight of the aqueous dispersion.  
   
   
       14 . The aqueous dispersion for chemical mechanical polishing according to  claim 6 , wherein the content of surface active agent is from 0.001 to 0.5% by weight of the aqueous dispersion.  
   
   
       15 . A chemical mechanical polishing process comprising: 
 a step of bringing a semiconductor substrate having a metal film into contact with a polishing pad attached to a turntable; and    a step of polishing a surface of the metal film while dropping the aqueous dispersion of claim ion the polishing pad.    
   
   
       16 . A process for producing semiconductor devices, comprising: 
 a step of forming an insulating film on a semiconductor substrate;    a step of forming a concave groove in the insulating film;    a step of depositing a metal in the concave groove and on the insulating film to form a metal film; and    a step of removing at least part of the metal film deposited on the insulating film by chemical mechanical polishing using the aqueous dispersion of  claim 1 .    
   
   
       17 . A kit for preparing an aqueous dispersion for chemical mechanical polishing, the kit comprising a liquid (I) and a liquid (II), the liquids being mixed to give the aqueous dispersion of  claim 1 , wherein 
 the liquid (I) is an aqueous dispersion containing water, the polyvinylpyrrolidone, the protective film-forming agent and the abrasive grains, and    the liquid (II) contains water and the oxidant.    
   
   
       18 . A kit for preparing an aqueous dispersion for chemical mechanical polishing, the kit comprising a liquid (III) and a liquid (IV), the liquids being mixed to give the aqueous dispersion of  claim 1 , wherein 
 the liquid (III) is an aqueous dispersion containing water and the abrasive grains,    the liquid (IV) contains water and the protective film-forming agent,    the liquid (III) and/or the liquid (IV) contain the polyvinylpyrrolidone, and    the liquid (III) and/or the liquid (IV) contain the oxidant.    
   
   
       19 . A kit for preparing an aqueous dispersion for chemical mechanical polishing, the kit comprising a liquid (V), a liquid (VI) and a liquid (VII), the liquids being mixed to give the aqueous dispersion of  claim 1 , wherein 
 the liquid (V) is an aqueous dispersion containing water and the abrasive grains,    the liquid (VI) contains water and the protective film-forming agent,    the liquid (VII) containing water and the oxidant, and    at least one of the liquids (V), (VI) and (VII) contain the polyvinylpyrrolidone.