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 protective-film-forming agent, a water-soluble polymer excluding poly(oxyethylene)lauryl ether, polyvinyl alcohol, gelatin and carboxymethylcellulose, and water.  
     
     
         2 . The polishing medium for chemical-mechanical polishing according to  claim 1 , further comprising a metal-oxide-dissolving agent.  
     
     
         3 . The polishing medium for chemical-mechanical polishing according to  claim 1 , which has a coefficient of kinetic friction of 0.25 or more.  
     
     
         4 . 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.  
     
     
         5 . 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.  
     
     
         6 . 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.  
     
     
         7 . The polishing medium for chemical-mechanical polishing according to  claim 2 , 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.  
     
     
         8 . The polishing medium for chemical-mechanical polishing according to  claim 1 , wherein said protective-film-forming agent is a nitrogen-containing compound.  
     
     
         9 . 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.  
     
     
         10 . 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 .  
     
     
         11 . The polishing method according to  claim 10 , wherein said polishing object film comprises at least one of copper, a copper alloy, a copper oxide and a copper alloy oxide.  
     
     
         12 . The polishing medium for chemical-mechanical polishing according to  claim 1 , which has a coefficient of kinetic friction of 0.25 or more.  
     
     
         13 . The polishing medium for chemical-mechanical polishing according to  claim 12 , 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.  
     
     
         14 . The polishing medium for chemical-mechanical polishing according to  claim 13 , which has a point-of-inflection pressure of 5 kPa (50 gf/cm 2 ) or more.  
     
     
         15 . 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.  
     
     
         16 . 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.  
     
     
         17 . The polishing medium for chemical-mechanical polishing according to  claim 8 , wherein said water-soluble polymer is selected from the group consisting of polysaccharides excluding carboxymethylcellulose, polycarboxylic acids and esters and salts thereof, and vinyl polymers excluding polyvinyl alcohol.  
     
     
         18 . The polishing medium for chemical-mechanical polishing according to  claim 9 , wherein said water-soluble polymer is selected from the group consisting of pectic acid, agar, polymalic acid, polymethacrylic acid, polyacrylic acid, polyacrylamide, and polyvinyl pyrrolidone, and esters and ammonium salts thereof.  
     
     
         19 . The polishing medium for chemical-mechanical polishing according to  claim 3 , which has a coefficient of kinetic friction of 0.35 or more.  
     
     
         20 . The polishing medium for chemical-mechanical polishing according to  claim 19 , which has a coefficient of kinetic friction of 0.45 or more.  
     
     
         21 . The polishing medium for chemical-mechanical polishing according to  claim 4 , which has a Ubbelode's viscosity in the range of 0.96 to 1.3 mPa·s.  
     
     
         22 . The polishing medium for chemical-mechanical polishing according to  claim 21 , which has a Ubbelode's viscosity in the range of 0.97 to 1.0 mPa·s.  
     
     
         23 . The polishing medium for chemical-mechanical polishing according to  claim 5 , which has a point-of-inflection pressure of 10 kPa (100 gf/cm 2 ) or more.  
     
     
         24 . The polishing medium for chemical-mechanical polishing according to  claim 5 , wherein said water-soluble polymer is selected from the group consisting of polysaccharides excluding carboxymethylcellulose, polycarboxylic acids and esters and salts thereof, and vinyl polymers excluding polyvinyl alcohol.  
     
     
         25 . The polishing medium for chemical-mechanical polishing according to  claim 5 , wherein said water-soluble polymer is selected from the group consisting of pectic acid, agar, polymalic acid, polymethacrylic acid, polyacrylic acid, polyacrylamide, and polyvinyl pyrrolidone, and esters and ammonium salts thereof.  
     
     
         26 . The polishing medium for chemical-mechanical polishing according to  claim 8 , wherein said nitrogen-containing compound is selected from the group consisting of ammonia, alkylamines, amino acids, imines, azoles, and salts thereof.  
     
     
         27 . The polishing medium for chemical-mechanical polishing according to  claim 17 , wherein said nitrogen-containing compound is selected from the group consisting of ammonia, alkylamines, amino acids, imines, azoles, and salts thereof.  
     
     
         28 . The polishing medium for chemical-mechanical polishing according to  claim 2 , wherein said protective-film-forming agent is at least one selected from the group consisting of chitosan, ethylenediaminetetraacetic acid, L-tryptophane, cuperazone, triazinedithiol, benzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole butyl ester, tolyltriazole and naphthotriazole.  
     
     
         29 . A polishing medium for chemical-mechanical polishing, comprising an oxidizing agent, a protective-film-forming agent, a water-soluble polymer and water, wherein the water-soluble polymer is at least one selected from the group consisting of polycarboxylic acids, polycarboxylic esters, and salts thereof.