Chemical mechanical polishing compositions and methods relating thereto

Abstract

A polishing composition for removing metal by CMP comprises, a metal oxidizer, an oxide inhibitor, a complexing agent, and an engineered copolymer comprising, molecules of a first moiety having hydrophilic functional groups forming bonds with the metal, and molecules of a second moiety having hydrophobic functional groups.

1 . A polishing composition for removing metal by CMP comprises, a metal oxidizer, an oxide inhibitor and a complexing agent, further characterised by; 
 an engineered copolymer comprising, molecules of a first moiety having hydrophilic functional groups forming bonds with the metal, and further comprising, molecules of a second moiety having hydrophobic functional groups that engage a polishing pad during CMP for the pad to remove the engineered copolymer from a surface of the metal, which enables removal of the metal by CMP, while minimizing removal of the engineering copolymer from recessed circuit interconnects to minimize dishing.    
     
     
         2 . The polishing composition as in  claim 1 , wherein said engineered copolymer is selected from a group consisting of; random copolymers, block copolymers, branched copolymers and alternating copolymers.  
     
     
         3 . The polishing composition as in  claim 1  wherein the engineered copolymer is present at a concentration up to about 1% by weight.  
     
     
         4 . The polishing composition as in  claim 1 , further characterised by; abrasive particles up to about 3% by weight.  
     
     
         5 . A polishing composition as in  claim 1  wherein the engineered copolymer is derived from an acrylic acid monomer and a methacrylic acid monomer at a mole ratio of acrylic acid monomer to methacrylic acid monomer in a range of, about 1:20 to about 20:1.  
     
     
         6 . A polishing composition as in  claim 1  wherein the engineered copolymer is derived from a mixture of ethylenically unsaturated monomers.  
     
     
         7 . A polishing composition as in  claim 1  wherein the engineered copolymer has a concentration up to about 1% by weight, the oxidizing agent has a concentration up to about 15% by weight, the complexing agent has a concentration up to about 3% by weight, and the inhibitor has a concentration up to about 2% by weight.  
     
     
         8 . A method for removing metal by CMP, comprising: polishing the metal with a polishing pad and a polishing composition, the polishing composition having, a metal oxidizer, an oxide inhibitor, a complexing agent, and an engineered copolymer comprising, molecules of a first moiety having hydrophilic functional groups forming bonds with the metal, and further comprising, molecules of a second moiety having hydrophobic functional groups that engage the polishing pad during CMP for the pad to remove the engineered copolymer from a surface of the metal, which enables removal of the metal by CMP while minimizing removal of the engineering copolymer from recessed circuit interconnects to minimize dishing.  
     
     
         9 . The method as in  claim 8  wherein the polishing composition further comprises abrasive particles of a concentration up to about 3% by weight.  
     
     
         10 . An aqueous polishing composition for selectively removing a portion of a metal layer from a semiconductor substrate during semiconductor device fabrication, comprising: at least one engineered copolymer, wherein said engineered copolymer comprises a first moiety and a second moiety, said first moiety comprising a hydrophilic functional group and said second moiety being relatively less hydrophilic than the first moiety.  
     
     
         11 . polishing composition in accordance with  claim 11  wherein the first moiety comprises a hydrophilic functional group with an affinity for the semiconductor substrate surface.  
     
     
         12 . A polishing composition in accordance with  claim 11  wherein the second moiety comprises a hydrophobic functional group which interacts with the polishing pad surface.  
     
     
         13 . A polishing composition in accordance with  claim 11  wherein said engineered copolymer is selected from a group consisting of random, block, branched and alternating copolymers.  
     
     
         14 . A polishing composition in accordance with  claim 13  wherein at least one engineered copolymer component is present at a concentration up to about 1% by weight of said composition.  
     
     
         15 . A polishing composition in accordance with  claim 14  further comprising abrasive particles up to about 3% by weight of said composition.  
     
     
         16 . A polishing composition in accordance with  claim 15  further comprising an oxidizing agent up to about 15% by weight of said composition.  
     
     
         17 . A polishing composition in accordance with  claim 16  further comprising a complexing agent up to about 3% by weight of said composition.  
     
     
         18 . A polishing composition in accordance with  claim 17  further comprising an inhibitor up to about 2% by weight of said composition.  
     
     
         19 . A polishing composition in accordance with  claim 18  wherein said copolymer is derived from a mixture comprising acrylic acid monomer and methacrylic acid monomer at a mole ratio of acrylic acid monomer to methacrylic acid monomer of about 1:20 to about 20:1.  
     
     
         20 . A polishing composition in accordance with  claim 19  wherein the copolymer has a weight average molecular weight in a range of about 20,000 to about 30,000.  
     
     
         21 . A polishing composition in accordance with  claim 20  further having a pH less than 5.  
     
     
         22 . A polishing composition in accordance with  claim 16  wherein the oxidizing agent is hydrogen peroxide.  
     
     
         23 . A polishing composition in accordance with  claim 17  wherein the complexing agent is malic acid.  
     
     
         24 . A polishing composition in accordance with  claim 18  wherein the inhibitor is an aromatic triazole.  
     
     
         25 . A polishing composition of  claim 13  wherein said engineered copolymer comprises the reaction product derived from a mixture of two or more ethylenically unsaturated monomers.  
     
     
         26 . A polishing composition in accordance with  claim 25  wherein at least 50% by weight of said mixture is an unsaturated carboxylic acid monomer.  
     
     
         27 . A method for selectively removing a portion of a metal layer from a semiconductor substrate, during semiconductor device fabrication, comprising: 
 providing a substrate having a metal layer requiring removal;    providing a polishing pad;    biasing said substrate and said polishing pad under a pressure; and    dispensing a polishing composition comprising at least one engineered copolymer, wherein said engineered copolymer comprises a first moiety and a second moiety, said first moiety comprising a hydrophilic functional group and said second moiety being relatively less hydrophilic than the first moiety.    
     
     
         28 . A method in accordance with  claim 18  performed utilizing a polishing composition wherein the first moiety comprises a hydrophilic functional group with an affinity for the semiconductor substrate surface.  
     
     
         29 . A method in accordance with  claim 27  performed utilizing a polishing composition wherein the second moiety comprises a hydrophobic functional group which interacts with the polishing pad surface.  
     
     
         30 . A method in accordance with  claim 27  wherein said engineered copolymer is selected from a group consisting of random, block, branched and alternating copolymers.  
     
     
         31 . A method in accordance with  claim 27  performed on a semiconductor substrate containing a copper layer requiring removal and copper interconnects utilizing an aqueous polishing composition comprising: 
 at least one engineered copolymer up to about 1% by weight of said composition;  
 an oxidizing agent up to about 15% by weight of said composition;  
 a complexing agent up to about 3% by weight of said composition; and  
 an inhibitor up to about 2% by weight of said composition.  
 
     
     
         32 . A method in accordance with  claim 31  performed utilizing a polishing composition further comprising abrasive particles up to about 3% by weight of said composition.  
     
     
         33 . A method in accordance with  claim 27  performed utilizing a polishing composition containing a copolymer derived from a mixture comprising acrylic acid monomer and methacrylic acid monomer at a mole ratio of acrylic acid monomer to methacrylic acid monomer of about 1:20 to about 20:1.  
     
     
         34 . A method in accordance with  claim 33  performed utilizing a polishing composition containing a copolymer derived from a mixture comprising acrylic acid monomer and methacrylic acid monomer at a mole ratio of acrylic acid monomer to methacrylic acid monomer of about 1:20 to about 20:1, said copolymer further having a molecular weight in a range of about 20,000 to about 30,000.  
     
     
         35 . A method in accordance with claim  31 performed utilizing a polishing composition comprising: at least one engineered copolymer up to about 1% by weight of said composition; an oxidizing agent up to about 15% by weight of said composition; a complexing agent up to about 3% by weight of said composition; an inhibitor up to about 2% by weight of said composition; and a pH less than 5.