Polishing slurries for chemical-mechanical polishing

Abstract

The aqueous slurries according to the present invention include soluble salts of molybdenum dissolved in an oxidizing agent and deionized water. Other aqueous polishing slurries include dissolved and undissolved nanoparticles of MoO 3 in a solution of deionized water and an oxidizing agent.

1 . A slurry for chemical mechanical planarization of a copper layer on a semiconductor substrate, comprising:
 a solution of deionized water and an oxidizing agent, the oxidizing agent being in a first amount;   a soluble salt of molybdenum dissolved in the solution, the soluble salt of molybdenum being in a second amount; and   at least two complexing agents, the complexing agents each being in the second amount.   
   
   
       2 . The slurry of  claim 1 , wherein the second amount is not more than the first amount. 
   
   
       3 . The slurry of  claim 1 , wherein the first amount is in a range from about 0.1 weight percent to about 1.0 weight percent of the total weight percent of the slurry. 
   
   
       4 . The slurry of  claim 1 , wherein the complexing agents are selected from the group consisting of glycine (C 2 H 5 NO 2 ), alanine (C 3 H 7 NO 2 ), amino butyric acid (C 4 H 9 NO 2 ) ethylene diamine (C 2 H 8 N 2 ), ethylene diamine tetra acetic acid (EDTA), citric acid (C 6 H 8 O 7 ), phthalic acid (C 6 H 4 (COOH) 2 ), oxalic acid (C 2 H 2 O 4 ), acetic acid (C 2 H 4 O 2 ), and succinic acid (C 4 H 6 O 4 ). 
   
   
       5 . The slurry of  claim 1 , further comprising ceramic/metallic nanoparticles, the ceramic/metallic nanoparticles being in an amount greater than the first amount. 
   
   
       6 . An aqueous slurry for polishing copper, comprising MoO 3  in an aqueous oxidizing agent solution, the MoO 3  consisting of dissolved and undissolved nanoparticles, the dissolved nanoparticles of MoO 3  comprising molybdic acid. 
   
   
       7 . The aqueous slurry of  claim 6 , wherein the aqueous slurry exhibits chemical reactivity with copper. 
   
   
       8 . The aqueous slurry of  claim 6 , further comprising supplemental ceramic/metallic nanoparticles. 
   
   
       9 . The aqueous slurry of  claim 6 , wherein the supplemental ceramic/metallic nanoparticles have a mean particle size of about 20 nanometers. 
   
   
       10 . The aqueous slurry of  claim 6 , further comprising a mixture of at least two complexing agents. 
   
   
       11 . The aqueous slurry of  claim 10  wherein the mixture of the at least two complexing agents comprises at least two complexing agents selected from the group consisting of glycine (C 2 H 5 NO 2 ), alanine (C 3 H 7 NO 2 ), amino butyric acid (C 4 H 9 NO 2 ) ethylene diamine (C 2 H 8 N 2 ), ethylene diamine tetra acetic acid (EDTA), citric acid (C 6 H 8 O 7 ), phthalic acid (C 6 H 4 (COOH) 2 ), oxalic acid (C 2 H 2 O 4 ), acetic acid (C 2 H 4 O 2 ), and succinic acid
 (C 4 H 6 O 4 ).   
   
   
       12 . An aqueous slurry for chemical mechanical planarization of copper, comprising molybdic acid powder dissolved in a solution of deionized water and an oxidizing agent, the molybdic acid powder comprising one or more selected from the group consisting of phosphotungstomolybdic acid and vanadiomolybdic acid. 
   
   
       13 . The aqueous slurry of  claim 12 , wherein the slurry comprises about 0.1% to about 10% by weight of the molybdic acid powder. 
   
   
       14 . The aqueous slurry of  claim 12 , wherein the oxidizing agent comprises one or more selected from the group consisting of hydrogen peroxide, ferric nitrate, potassium iodate, nitric acid, potassium permanganate, potassium persulfate, ammonium persulfate, potassium periodate, and hydroxylamine. 
   
   
       15 . The aqueous slurry of  claim 12 , further comprising ceramic/metallic oxide particles. 
   
   
       16 . The aqueous slurry of  claim 12 , wherein the oxidizing agent comprises at least one selected from the group consisting of potassium iodate, potassium permanganate, potassium persulfate, and potassium periodate. 
   
   
       17 . An aqueous slurry for chemical mechanical planarization of a copper layer on a semiconductor substrate, comprising a soluble salt of molybdenum visibly dissolved in a solution of deionized water and an oxidizing agent, the soluble salt of molybdenum comprising one or more selected from the group consisting of a potassium molybdate and an iron molybdate. 
   
   
       18 . A slurry for chemical mechanical polishing of copper, comprising ions selected from the group consisting of per-molybdate ions and peroxy-molybdate ions, the ions being in a solution comprising deionized water and an oxidizing agent. 
   
   
       19 . The slurry of  claim 18 , further comprising at least two complexing agents. 
   
   
       20 . The slurry of  claim 18 , further comprising a copper corrosion inhibitor. 
   
   
       21 . An aqueous slurry for chemical mechanical planarization of copper comprising about 0.1 to less than one weight percent of MoO 3  dissolved in an oxidizing agent. 
   
   
       22 . The aqueous slurry of  claim 21 , wherein the about 0.1 to less than one weight percent of MoO 3  is about 0.1 to about 0.5 weight percent of MoO 3 . 
   
   
       23 . The aqueous slurry of  claim 21 , wherein the oxidizing agent comprises at least one selected from the group consisting of potassium iodate, potassium permanganate, potassium persulfate, and potassium periodate. 
   
   
       24 . The aqueous slurry of  claim 21 , wherein the oxidizing agent is ferric nitrate. 
   
   
       25 . The aqueous slurry of  claim 21 , further comprising at least one surfactant selected from the group consisting of polyacrylic acid, a carboxylic acid and its salt, a sulfuric ester and its salt, a sulfonic acid and its salt, a phosphoric acid and its salt, a sulfosuccinic acid and its salt, and cetyl trimethyl ammonium tosylate (CTAT).