Polishing slurry and method for chemical-mechanical polishing of copper

Abstract

The claimed invention involves a novel aqueous polishing slurry for chemical-mechanical polishing that is effective for polishing copper at high polish rates. The aqueous slurry according to the present invention comprises particles of MoO 2 in an oxidizing agent. A method for polishing copper by chemical-mechanical polishing includes contacting copper with a polishing pad and an aqueous slurry comprising particles of MoO 2 in an oxidizing agent.

1 . An aqueous polishing slurry for chemical-mechanical polishing, comprising particles of MoO 2  and an oxidizing agent.  
     
     
         2 . The aqueous polishing slurry of  claim 1 , wherein said polishing slurry comprises about 0.5% to about 10% by weight particles of MoO 2 .  
     
     
         3 . The aqueous polishing slurry of  claim 1 , wherein said polishing slurry comprises about 1% to about 3% by weight particles of MoO 2 .  
     
     
         4 . The aqueous polishing slurry of  claim 1 , wherein said polishing slurry comprises about 3% by weight particles of MoO 2 .  
     
     
         5 . The aqueous polishing slurry of  claim 1 , wherein the particles of MoO 2  have a mean particle size in the range of about 25 nanometers to about 1 micron.  
     
     
         6 . The aqueous polishing slurry of  claim 1 , wherein the particles of MoO 2  have a mean particle size in the range of about 25 nanometers to about 560 nanometers.  
     
     
         7 . The aqueous polishing slurry of  claim 1 , wherein the particles of MoO 2  have a mean particle size in the range of about 50 nanometers to about 200 nanometers.  
     
     
         8 . The aqueous polishing slurry of  claim 1 , wherein said oxidizing agent comprises one or more selected from the group consisting of ferric nitrate, nitric acid, potassium iodide, and potassium iodate.  
     
     
         9 . The aqueous polishing slurry of  claim 1 , wherein said oxidizing agent comprises one or more selected from the group consisting of hydroxylamine hydrochloride and potassium permanganate.  
     
     
         10 . The aqueous polishing slurry of  claim 1 , wherein said oxidizing agent is potassium iodate.  
     
     
         11 . The aqueous polishing slurry of  claim 1 , further comprising an acid or a base for adjusting the pH of said polishing slurry within the range of from about 1 to about 14.  
     
     
         12 . The aqueous polishing slurry of  claim 1 , further comprising an acid or a base for adjusting the pH of said polishing slurry within the range of from about 3 to about 7.  
     
     
         13 . The aqueous polishing slurry of  claim 1 , further comprising an acid or a base for adjusting the pH of said polishing slurry to about 4.  
     
     
         14 . The aqueous polishing slurry of  claim 1 , wherein said polishing slurry further comprises an anionic surfactant.  
     
     
         15 . The aqueous polishing slurry of  claim 14 , wherein said anionic surfactant comprises one or more selected from the group consisting of polyacrylic acid, a carbolic acid or its salt, a sulfuric ester or its salt, a sulfonic acid or its salt, a phosphoric acid or its salt, and a sulfosuccinic acid or its salt.  
     
     
         16 . The aqueous polishing slurry of  claim 14 , wherein said anionic surfactant is polyacrylic acid.  
     
     
         17 . The aqueous polishing slurry of  claim 1 , wherein said polishing slurry further comprises a cationic surfactant.  
     
     
         18 . The aqueous polishing slurry of  claim 17 , wherein said cationic surfactant comprises one or more selected from the group consisting of a primary amine or its salt, a secondary amine or its salt, a tertiary amine or its salt, and a quaternary amine or its salt.  
     
     
         19 . The aqueous polishing slurry of  claim 17 , wherein said cationic surfactant is cetyl pyridinium chloride.  
     
     
         20 . The aqueous polishing slurry of  claim 1 , further comprising a copper passivating agent.  
     
     
         21 . The aqueous polishing slurry of  claim 20 , wherein said copper passivating agent comprises a heterocyclic organic compound.  
     
     
         22 . The aqueous polishing slurry of  claim 20 , wherein the copper passivating agent comprises one or more selected from the group consisting of benzotriazole, triazole, and benzimidazole.  
     
     
         23 . The aqueous polishing slurry of  claim 1  further comprising supplemental metal oxide particles.  
     
     
         24 . The aqueous polishing slurry of  claim 23 , wherein said supplemental metal oxide particles comprise one or more selected from the group consisting of silica, ceria, aluminia, zirconia, titania, magnesia, iron oxide, tin oxide, and germania.  
     
     
         25 . The aqueous polishing slurry of  claim 1 , wherein said polishing slurry further comprises molybdenum sulfide particles.  
     
     
         26 . The aqueous polishing slurry of  claim 1 , wherein said polishing slurry further comprises about 0.1% to about 10% by weight molybdenum sulfide particles.  
     
     
         27 . The aqueous polishing slurry of  claim 1 , wherein said polishing slurry further comprises about 0.5% to about 5% by weight molybdenum sulfide particles.  
     
     
         28 . The aqueous polishing slurry of  claim 1 , wherein said polishing slurry further comprises about 1% by weight molybdenum sulfide particles.  
     
     
         29 . The aqueous polishing slurry of  claim 1 , wherein said slurry further comprises ethylene diamine tetra acetic acid.  
     
     
         30 . A method for producing MoO 2 , comprising: 
 providing a supply of MoO 3 ;    heating said supply of MoO 3  in a reducing atmosphere to a temperature in the range of about 400° C. to about 700° C. for a time in the range of about 30 minutes to about 180 minutes.    
     
     
         31 . The method of  claim 30 , wherein said reducing atmosphere comprises hydrogen.  
     
     
         32 . A method for polishing copper by chemical-mechanical polishing comprising polishing copper using a polishing pad and an aqueous slurry comprising MoO 2  and an oxidizing agent.  
     
     
         33 . The method of  claim 32 , wherein said slurry comprises about 0.5% to about 10% by weight particles of MoO 2 .  
     
     
         34 . The method of  claim 32 , wherein said slurry comprises about 1% to about 3% by weight particles of MoO 2 .  
     
     
         35 . The method of  claim 32 , wherein said slurry comprises about 3% by weight particles of MoO 2 .  
     
     
         36 . The method of  claim 32 , wherein the particles of MoO 2  have a mean particle size in the range of about 25 nanometers to about 1 micron.  
     
     
         37 . The method of  claim 32 , wherein the particles of MoO 2  have a mean particle size in the range of about 25 nanometers to about 560 nanometers.  
     
     
         38 . The method of  claim 32 , wherein the particles of MoO 2  have a mean particle size in the range of about 50 nanometers to about 200 nanometers.  
     
     
         39 . The method of  claim 32 , wherein said oxidizing agent comprises one or more selected from the group consisting of ferric nitrate, nitric acid, potassium iodide, and potassium iodate.  
     
     
         40 . The method of  claim 32 , wherein said oxidizing agent comprises one or more selected from the group consisting of hydroxylamine hydrochloride and potassium permanganate.  
     
     
         41 . The method of  claim 32 , wherein said oxidizing agent is potassium iodate.  
     
     
         42 . The method of  claim 32 , further comprising an acid or a base for adjusting the pH of said slurry within the range of from about 1 to about 14.  
     
     
         43 . The method of  claim 32 , further comprising an acid or a base for adjusting the pH of said slurry within the range of from about 3 to about 7.  
     
     
         44 . The method of  claim 32 , further comprising an acid or a base for adjusting the pH of said slurry to about 4.  
     
     
         45 . The method of  claim 32 , wherein said slurry further comprises an anionic surfactant.  
     
     
         46 . The method of  claim 45 , wherein said anionic surfactant comprises one or more selected from the group consisting of polyacrylic acid, a carbolic acid or its salt, a sulfuric ester or its salt, a sulfonic acid or its salt, a phosphoric acid or its salt, and a sulfosuccinic acid or its salt.  
     
     
         47 . The method of  claim 45 , wherein said anionic surfactant is polyacrylic acid.  
     
     
         48 . The method of  claim 32 , wherein said polishing slurry further comprises a cationic surfactant.  
     
     
         49 . The method of  claim 48 , wherein said cationic surfactant comprises one or more selected from the group consisting of a primary amine or its salt, a secondary amine or its salt, a tertiary amine or its salt, and a quaternary amine or its salt.  
     
     
         50 . The method of  claim 48 , wherein said cationic surfactant is cetyl pyridinium chloride.  
     
     
         51 . The method of  claim 32 , further comprising a copper passivating agent.  
     
     
         52 . The method of  claim 51 , wherein said copper passivating agent comprises a heterocyclic organic compound.  
     
     
         53 . The method of  claim 51 , wherein the copper passivating agent comprises one or more selected from the group consisting of benzotriazole, triazole, and benzimidazole.  
     
     
         54 . The method of  claim 32  further comprising supplemental metal oxide particles.  
     
     
         55 . The aqueous polishing slurry of  claim 54 , wherein said supplemental metal oxide particles comprise one or more selected from the group consisting of silica, ceria, aluminia, zirconia, titania, magnesia, iron oxide, tin oxide, and germania.  
     
     
         56 . The method of  claim 32 , wherein said slurry further comprises molybdenum sulfide particles.  
     
     
         57 . The method of  claim 32 , wherein said slurry further comprises about 0.1% to about 10% by weight molybdenum sulfide particles.  
     
     
         58 . The method of  claim 32 , wherein said slurry further comprises about 0.5% to about 5% by weight molybdenum sulfide particles.  
     
     
         59 . The method of  claim 32 , wherein said slurry further comprises about 1% by weight molybdenum sulfide particles.  
     
     
         60 . The method of  claim 32 , further comprising additionally polishing the copper with a dilute suspension of H 2 O 2 , glycine, BTA, and colloidal silica in de-ionized water at a pH of 4.