Method for planarizing organosilicate layers

Abstract

A method for planarizing an organosilicate layer is provided. The organosilicate material layer is planarized using a slurry in conjunction with a chemical mechanical polishing (CMP) process. The slurry comprises an abrasive material dispersed in a suitable solvent. The slurry preferably has a pH greater than about 9. The abrasive material preferably has an average particle size greater than about 35 nm (nanometers).

What is claimed is:  
     
         1 . A composition for planarizing an organosilicate layer, comprising: 
 a slurry including an abrasive material dispersed in a solvent, wherein the slurry has a pH greater than about 9.    
     
     
         2 . The composition of  claim 1  wherein the abrasive material is selected from the group consisting of silica (SiO 2 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), titanium oxide (TiO 2 ), and combinations thereof.  
     
     
         3 . The composition of  claim 1  wherein the abrasive material has an average particle size greater than about 35 nm (nanometers).  
     
     
         4 . The composition of  claim 1  wherein the pH of the slurry is adjusted by adding a source of hydroxyl ions thereto.  
     
     
         5 . The composition of  claim 4  wherein the source of hydroxyl ions is selected from the group consisting of potassium hydroxide (KOH), ammonium hydroxide (NH 4 OH), sodium hydroxide (NaOH), calcium hydroxide (CaOH), magnesium hydroxide (MgOH), and combinations thereof.  
     
     
         6 . The composition of  claim 1  wherein the slurry further comprises one or more materials selected from the group consisting of chelating agents, buffers, oxidizers, and corrosion inhibitors.  
     
     
         7 . The composition of  claim 1  wherein the concentration of the abrasive material in the slurry is within a range of about 10% by weight to about 60% by weight.  
     
     
         8 . A method for planarizing an organosilicate layer, comprising: 
 positioning a substrate having an organosilicate layer thereon in a polishing system;    providing a slurry including an abrasive material dispersed in a solvent to the polishing system, wherein the slurry has a pH greater than about 9.0; and    polishing the organosilicate layer using the slurry.    
     
     
         9 . The method of  claim 8  wherein the abrasive material is selected from the group consisting of silica (SiO 2 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), titanium oxide (TiO 2 ), and combinations thereof.  
     
     
         10 . The method of  claim 8  wherein the abrasive material has an average particle size greater than about 35 nm (nanometers).  
     
     
         11 . The method of  claim 8  wherein the pH of the slurry is adjusted by adding a source of hydroxyl ions thereto.  
     
     
         12 . The method of  claim 11  wherein the source of hydroxyl ions is selected from the group consisting of potassium hydroxide (KOH), ammonium hydroxide (NH 4 OH), sodium hydroxide (NaOH), calcium hydroxide (CaOH), magnesium hydroxide (MgOH).  
     
     
         13 . The method of  claim 8  wherein the slurry further comprises one or more materials selected from the group consisting of chelating agents, buffers, oxidizers, corrosion inhibitors, and combinations thereof.  
     
     
         14 . The method of  claim 8  wherein the concentration of abrasive material in the slurry is within a range of about 10% by weight to about 60% by weight.  
     
     
         15 . The method of  claim 8  wherein the organosilicate layer is polished by placing it in contact with a polishing pad, the polishing pad having the slurry thereon, and wherein the polishing pad is disposed upon a rotatable platen.  
     
     
         16 . The method of  claim 15  wherein the polishing pad comprises polyurethane.  
     
     
         17 . The method of  claim 15  wherein the organosilicate layer contacts the polishing pad with a pressure within range of about 1 psi (pounds/square inch) to about 14 psi.  
     
     
         18 . The method of  claim 15  wherein the platen rotates at a speed within the range of about 0.1 m/s (meters/second) to about 2 m/s.  
     
     
         19 . A method for fabricating a device, comprising: 
 providing a substrate having conductive features formed thereon with an organosilicate layer deposited between and on top of the conductive features;    positioning the substrate in a polishing system;    providing a slurry including an abrasive material dispersed in a solvent to the polishing system, wherein the slurry has a pH greater than about 9; and    polishing the organosilicate layer using the slurry.    
     
     
         20 . The method of  claim 19  wherein the abrasive material is selected from the group consisting of silica (SiO 2 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ), titanium oxide (TiO 2 ), and combinations thereof.  
     
     
         21 . The method of  claim 19  wherein the abrasive material has an average particle size greater than about 35 nm (nanometers).  
     
     
         22 . The method of  claim 19  wherein the pH of the slurry is adjusted by adding a source of hydroxyl ions thereto.  
     
     
         23 . The method of  claim 22  wherein the source of hydroxyl ions is selected from the group consisting of potassium hydroxide (KOH), ammonium hydroxide (NH 4 OH), sodium hydroxide (NaOH), calcium hydroxide (CaOH), and magnesium hydroxide (MgOH).  
     
     
         24 . The method of  claim 19  wherein the slurry further comprises one or more materials selected from the group consisting of chelating agents, buffers, oxidizers, corrosion inhibitors, and combinations thereof.  
     
     
         25 . The method of  claim 19  wherein the concentration of abrasive material in the slurry is within a range of about 10% by weight to about 60% by weight.  
     
     
         26 . The method of  claim 19  wherein the organosilicate layer is polished by placing it in contact with a polishing pad having the slurry thereon, and wherein the polishing pad is disposed upon a rotatable platen.  
     
     
         27 . The method of  claim 26  wherein the polishing pad comprises polyurethane.  
     
     
         28 . The method of  claim 26  wherein the organosilicate layer contacts the polishing pad with a pressure within a range of about 1 psi (pounds/square inch) to about 4 psi.  
     
     
         29 . The method of  claim 26  wherein the platen rotates at a speed within a range of about 0.1 m/s (meters/second) to about 2.0 m/s.