Polishing medium for chemical-mechanical polishing, and polishing method

Abstract

This invention provides a polishing medium for CMP, comprising an oxidizing agent, a metal-oxide-dissolving agent, a protective-film-forming agent, a water-soluble polymer, and water, and a polishing method making use of this polishing medium. Also, it is preferable that the water-soluble polymer has a weight-average molecular weight of 500 or more and the polishing medium has a coefficient of kinetic friction of 0.25 or more, a Ubbelode's viscosity of from 0.95 mPa.s (0.95 cP) to 1.5 mPa.s (1.5 cP) and a point-of-inflection pressure of 5 kPa (50 gf/cm 2 ).

1 . A polishing medium for chemical-mechanical polishing, comprising an oxidizing agent, a metal-oxide-dissolving agent, a protective-film-forming agent, a water-soluble polymer, and water.  
     
     
         2 . The polishing medium for chemical-mechanical polishing according to  claim 1 , wherein said water-soluble polymer has a weight-average molecular weight of 500 or more.  
     
     
         3 . The polishing medium for chemical-mechanical polishing according to  claim 2 , wherein said water-soluble polymer comprises two or more polymers each having a weight-average molecular weight of 500 or more, wherein but a weight-average molecular weight of said polymers are different from each other.  
     
     
         4 . The polishing medium for chemical-mechanical polishing according to  claim 1 , which has a coefficient of kinetic friction of 0.25 or more.  
     
     
         5 . The polishing medium for chemical-mechanical polishing according to  claim 1 , which has a Ubbelode's viscosity of 0.95 mPa.s (0.95 cP) or more and 1.5 mPa.s (1.5 cP) or less.  
     
     
         6 . The polishing medium for chemical-mechanical polishing according to  claim 1 , which has a point-of-inflection pressure of 5 kPa (50 gf/cm 2 ) or more.  
     
     
         7 . The polishing medium for chemical-mechanical polishing according to  claim 1 , wherein said oxidizing agent is at least one of hydrogen peroxide, nitric acid, potassium periodate, hypochlorous acid and ozone water.  
     
     
         8 . The polishing medium for chemical-mechanical polishing according to  claim 1 , wherein said metal-oxide-dissolving agent is at least one of an organic acid, an organic-acid ester, an organic-acid ammonium salt and sulfuric acid.  
     
     
         9 . The polishing medium for chemical-mechanical polishing according to  claim 1 , wherein said protective-film-forming agent is a nitrogen-containing compound.  
     
     
         10 . The polishing medium for chemical-mechanical polishing according to  claim 1 , wherein said protective-film-forming agent is at least one of a mercaptan, glucose and cellulose.  
     
     
         11 . A polishing method comprising polishing a polishing object film of a metal or metal oxide with the polishing medium for chemical-mechanical polishing according to  claim 1 .  
     
     
         12 . The polishing method according to  claim 11 , wherein said polishing object film comprises at least one of copper, a copper alloy, a copper oxide and a copper alloy oxide.