Pre-coated particles for chemical mechanical polishing

Abstract

The present invention relates to the manufacture and use of novel pre-coated abrasive particles and particle slurries for the chemical mechanical polishing (CMP) of semiconductor wafers, thin films, inter-layer dielectric, metals, and other components during integrated circuit, flat panel display, or MEMS manufacturing. For example, polishing slurry abrasive particles can be pre-coated with additives, such as, inhibitors and/or surfactants during manufacture of the abrasive particles or slurry. The additive's opportunity to react directly with the abrasive particles early in the particle manufacturing process provides a slurry having a more stable, selectable, and predictable ratio of abrasive particles pre-coated with a more stable, selectable, and predictable amount and type of additives.

1 . A method comprising: 
 chemically-mechanically polishing a wafer with a polishing slurry, wherein the slurry comprises: 
 a solution; and  
 a selected ratio of coated abrasive particles as compared to abrasive particles not coated, wherein said coated abrasive particles comprise a selected number of a plurality of abrasive particles each coupled to at least one additive.  
   
   
   
       2 . The method of  claim 1 , wherein said wafer comprises a film formed on a substrate.  
   
   
       3 . The method of  claim 1 , wherein said ratio is substantially predictable with respect to time so that said particles can be successfully shipped and used in said polishing at another facility.  
   
   
       4 . The method of  claim 1 , wherein said polishing further comprises: 
 placing said wafer in contact with a polishing pad;    providing movement to said polishing pad; and    depositing the slurry onto said polishing pad.    
   
   
       5 . The method of  claim 1 , wherein the selected ratio comprises a first plurality of abrasive particles coated with a chemical mechanical polishing (CMP) additive during manufacturing of the selected ratio, a second plurality of abrasive particles not coated with a chemical mechanical polishing (CMP) additive during manufacturing of the ratio, and a ratio of the first plurality to the second plurality selected during manufacturing of the ratio.  
   
   
       6 . The method of  claim 1 , wherein said slurry is stable enough to be transported, from a location where said slurry was mixed, to a second location, and successfully used at least 30 minutes after mixing, for chemical-mechanical polishing at the second location.  
   
   
       7 . The method of  claim 1 , further comprising, prior to polishing: 
 transporting the slurry from a location where said slurry was mixed, to a second location;    waiting to use the slurry at the second location for at least 30 minutes.    
   
   
       8 . A composition comprising: 
 a plurality of manufactured abrasive particles having an abrasive characteristic suitable for use in a wafer polishing process during manufacture of circuit devices, said plurality of manufactured abrasive particles comprising;    a first number of pre-coated abrasive particles as compared to a second number of abrasive particles not coated, wherein said coated abrasive particles comprise a plurality of abrasive particles each coupled to at least a first chemical mechanical polishing (CMP) additive and a different second CMP additive, wherein neither the first CMP additive nor the second CMP additive is a precursor or a surfactant; and    a solution for polishing a surface.    
   
   
       9 . The composition of  claim 8 , wherein said plurality of manufactured abrasive particles comprise particles of a size suitable for a polishing slurry.  
   
   
       10 . The composition of  claim 8 , wherein said first CMP and second CMP additives are selected from the group consisting of an inhibitor an oxidant, and a chelating agent.  
   
   
       11 . The composition of  claim 8 , wherein the abrasive particles are selected from the group consisting of silica, ceria, alumina, titanium oxide, and diamond.  
   
   
       12 . The composition of  claim 8 , wherein the first, and second numbers are selectable with respect to time so that said slurry can be transported from a location where said slurry was mixed and the period of time is at least 30 minutes.  
   
   
       13 . A system for producing pre-coated abrasive particles for chemical-mechanical polishing, said system comprising: 
 a means for pre-coating abrasive particles with additives during fabrication of the abrasive particles, wherein said pre-coating abrasive particles comprises coating ones of a plurality of abrasive particles with at least one additive during manufacture of said pre-coated abrasive particles.    
   
   
       14 . The system of  claim 13  further comprising: 
 a means for providing a selected ratio of pre-coated abrasive particles as compared to the abrasive particles not pre-coated by the additive.    
   
   
       15 . The system of  claim 13 , further comprising: 
 a means for manufacturing a plurality abrasive particles by fuming or shear mixing;    a means for mixing the coated abrasive particles with a solution to form a polishing slurry.    
   
   
       16 . A method comprising: 
 pre-coating a plurality of abrasive particles with chemical mechanical polishing (CMP) additive after manufacturing of the abrasive particles; and mixing the pre-coated abrasive particles with a solution to form a polishing slurry; then    storing or transporting the slurry.    
   
   
       17 . The method of  claim 16 , wherein coating comprises shear mixing to from particles of a size suitable for a polishing slurry to polish electronic devices on silicon substrate.  
   
   
       18 . The method of  claim 16 , wherein manufacturing comprises one of fuming and shear mixing.  
   
   
       19 . The method of  claim 16 , wherein coating comprises introducing a plurality of additives to the plurality of abrasive particles to form a plurality of coated abrasive particles having a coating including the plurality of additives.  
   
   
       20 . The method of  claim 16 , wherein the plurality of abrasive particles comprise particles of approximately a first size and particles of approximately a second size to form first size coated particles having a coating including the plurality of additives, and a second size coated particles having a coating including the plurality of additives.