Dispersion for the chemical-mechanical polishing of metal surfaces containing metal oxide particles and a cationic polymer

Abstract

Aqueous dispersion for the chemical-mechanical polishing of metal surfaces, containing a metal oxide powder and a cationic, surface-active polymer, wherein the metal oxide powder is silicon dioxide, aluminium oxide or a mixed oxide of silicon dioxide and aluminium oxide, and the cationic, surface-active polymer is a polyallyl amine or polydiallyl amine dissolved in the dispersion and having a weight average molecular weight of less than 100,000 g/mol. The dispersion can be used for the chemical-mechanical polishing of metallic layers and of metallic films, which are applied to an insulating barrier layer.

1 . Aqueous dispersion for the chemical-mechanical polishing of metal surfaces, containing a metal oxide powder and a cationic, surface-active polymer, characterised in that 
 the metal oxide powder is silicon dioxide, aluminium oxide or a mixed oxide of silicon dioxide and aluminium oxide, and    the cationic, surface-active polymer is a polyallyl amine or polydiallyl amine dissolved in the dispersion and having a weight-average molecular weight of less than 100,000 g/mol.    
   
   
       2 . Aqueous dispersion for the chemical-mechanical polishing of metal surfaces according to  claim 1 , characterised in that the weight-average molecular weight of the cationic, surface-active polymer is 2000 to 50,000 g/mol.  
   
   
       3 . Aqueous dispersion for the chemical-mechanical polishing of metal surfaces according to  claim 1 , characterised in that the content of cationic, surface-active polymer is between 0.1 and 15 wt. %, relative to the amount of polymer and metal oxide.  
   
   
       4 . Aqueous dispersion for the chemical-mechanical polishing of metal surfaces according to  claim 1 , characterised in that the metal oxide powder is produced by flame hydrolysis.  
   
   
       5 . Aqueous dispersion for the chemical-mechanical polishing of metal surfaces according to  claim 1 , characterised in that the metal oxide powder is pyrogenically produced silicon dioxide.  
   
   
       6 . Aqueous dispersion for the chemical-mechanical polishing of metal surfaces according to  claim 1 , characterised in that the content of aluminium oxide as mixed oxide component of a metal oxide powder is between 60 and 99.9 wt. % or between 0.01 and 10 wt. %.  
   
   
       7 . Aqueous dispersion for the chemical-mechanical polishing of metal surfaces according to  claim 1 , characterised in that the average particle diameter or aggregate diameter of the metal oxide powder in the dispersion is less than 300 nm.  
   
   
       8 . Aqueous dispersion for the chemical-mechanical polishing of metal surfaces according to  claim 1 , characterised in that the content of metal oxide in the dispersion is 1 to 50 wt. %, relative to the total amount of dispersion.  
   
   
       9 . Aqueous dispersion for the chemical-mechanical polishing of metal surfaces according to  claim 1 , characterised in that the pH is 3 to 7.  
   
   
       10 . Aqueous dispersion for the chemical-mechanical polishing of metal surfaces according to  claim 1 , characterised in that it contains additives from the group comprising pH-adjusting substances, oxidising agents, oxidation activators and/or corrosion inhibitors.  
   
   
       11 . The method of using the aqueous dispersion according to  claim 1  for the chemical-mechanical polishing of metal layers.  
   
   
       12 . The method of using the aqueous dispersion according to  claim 1  for the chemical-mechanical polishing of metal layers applied to an insulating barrier layer.