Methods of polishing an object using slurry compositions

Abstract

In a slurry composition for chemical mechanical polishing, a method of preparing the slurry composition and a method of polishing an object using the slurry composition, the slurry composition includes a cerium oxide abrasive particle having a rare earth element other than cerium as a dopant, and an aqueous medium for dispersing the cerium oxide abrasive particle. The cerium oxide abrasive particle doped with the rare earth element may have an enhanced fracture strength as being compared with a pure cerium oxide abrasive particle, and also may reduce an amount of large or agglomerated particles and generation of a scratch on a polished surface of an object.

1 - 14 . (canceled) 
     
     
         15 . A method of chemically and mechanically polishing an object, comprising:
 providing a slurry composition between an object and a polishing pad, the slurry composition including a cerium oxide abrasive particle having a rare earth element as a dopant, and an aqueous medium for dispersing the cerium oxide abrasive particle, with the proviso that the rare earth element is not cerium; and   polishing a surface of the object by contacting the object with the polishing pad.   
     
     
         16 . The method of  claim 15 , wherein the object comprises:
 a substrate having a trench; and   an insulation layer on the substrate to fill the trench.   
     
     
         17 . The method of  claim 16 , wherein polishing the surface of the object comprises polishing the insulation layer until an upper face of the substrate is exposed to form an isolation layer in the trench. 
     
     
         18 . The method of  claim 15 , wherein the object comprises:
 a substrate on which a conductive structure is formed; and   an insulating interlayer on the substrate to cover the conductive structure.   
     
     
         19 . The method of claim  1 , wherein the rare earth element comprises samarium (Sm). 
     
     
         20 . The method of claim  1 , wherein an amount of the rare earth element is in a range of about 10 to about 40% by mole, based on a total mole of cerium and the rare earth element. 
     
     
         21 . The method of  claim 20 , wherein the amount of the rare earth element is in a range of about 20 to about 30% by mole, based on a total mole of cerium and the rare earth element. 
     
     
         22 . The method of claim  1 , wherein the cerium oxide abrasive particle has a mean grain diameter of less than about 29 nm. 
     
     
         23 . The method of claim  1 , wherein the ceria abrasive particle has a mean diameter of a secondary particle in a range of about 70 nm to about 120 nm. 
     
     
         24 . The method of claim  1 , wherein the cerium oxide abrasive particle doped with the rare earth element has a sphere-like grain. 
     
     
         25 . The method of claim  1 , wherein the aqueous medium comprises a dispersing agent and water, and an amount of the dispersing agent is in a range of about 0.05 to about 5% by weight, based on a total weight of the slurry composition. 
     
     
         26 . The method of claim  1 , wherein an amount of the cerium oxide abrasive particle is in a range of about 1 to about 10% by weight, based on a total weight of the slurry composition. 
     
     
         27 . The method of claim  1 , wherein the cerium oxide abrasive particle is prepared by performing a thermal treatment on a precipitate obtained by co-precipitating a cerium salt and a salt of a rare earth element in an aqueous solution, and by grinding the thermally treated precipitate, with the proviso that the rare earth element is not cerium.