Abrasive tool with flat and consistent surface topography for conditioning a cmp pad and method for making

Abstract

An abrasive tool with flat and consistent surface topography for conditioning a CMP pad and method for making are disclosed. The abrasive tool includes abrasive grains coupled to a low coefficient of thermal expansion (CTE) substrate through a metal bond. There is an overall CTE mismatch that ranges from about 0.1 μm/m-° C. to about 5.0 μm/m-° C. The overall CTE mismatch is the difference between the CTE mismatch of the abrasive grains and the metal bond and the CTE mismatch of the low CTE substrate and the metal bond.

What is claimed is: 
     
         1 . A method of forming an abrasive tool, comprising:
 providing a low coefficient of thermal expansion (CTE) substrate as a preform;   applying a metal bond to the low CTE substrate;   applying abrasive grains to the metal bond to form an as-made abrasive tool, wherein there is an overall CTE mismatch that ranges from about 0.1 μm/m-° C. to about 5.0 μm/m-° C., wherein the overall CTE mismatch is the difference between the CTE mismatch of the abrasive grains and the metal bond and the CTE mismatch of the low CTE substrate and the metal bond;   drying the as-made abrasive tool in an oven; and   firing the as-made abrasive tool in a furnace at a predetermined firing temperature to form the abrasive tool.   
     
     
         2 . The method according to  claim 1 , wherein the abrasive tool has a surface topography flatness of no more than about 150 μm. 
     
     
         3 . The method according to  claim 2 , wherein the abrasive tool has a surface topography flatness of no more than about 100 μm. 
     
     
         4 . The method according to  claim 3 , wherein the abrasive tool has a surface topography flatness of no more than about 70 μm. 
     
     
         5 . The method according to  claim 1 , further comprising applying a coating to a working surface of the abrasive tool. 
     
     
         6 . The method according to  claim 5 , wherein the coating is corrosion-resistant. 
     
     
         7 . The method according to  claim 5 , wherein the coating is selected from the group consisting of a fluorine-doped nanocomposite coating and a hydrophobic polymeric coating. 
     
     
         8 . The method according to  claim 7 , wherein the fluorine-doped nanocomposite coating and the hydrophobic polymeric coating comprise one or more additional dopants. 
     
     
         9 . The method according to  claim 5 , wherein the coating is hydrophobic. 
     
     
         10 . The method according to  claim 5 , wherein the coating is hydrophilic. 
     
     
         11 . The method according to  claim 1 , wherein the abrasive grains have a CTE range from about 1.0 μm/m-° C. to about 8.0 μm/m-° C. 
     
     
         12 . The method according to  claim 1 , wherein the metal bond has a CTE that ranges from about 5.0 μm/m-° C. to about 20.0 μm/m-° C. 
     
     
         13 . The method according to  claim 1 , wherein the low CTE substrate has a CTE that ranges from about 1.0 μm/m-° C. to about 10.0 μm/m-° C. 
     
     
         14 . The method according to  claim 1 , wherein the CTE of the low CTE substrate differs by no more than about 100% of the CTE of the abrasive grains. 
     
     
         15 . The method according to  claim 14 , wherein the CTE of the low CTE substrate differs by no more than about 50% of the CTE of the abrasive grains. 
     
     
         16 . The method according to  claim 15 , wherein the CTE of the low CTE substrate differs by no more than about 20% of the CTE of the abrasive grains. 
     
     
         17 . The method according to  claim 1 , wherein the abrasive grains are selected from the group consisting of oxides, borides, carbides, nitrides, diamond particles, cBN and combinations thereof. 
     
     
         18 . The method according to  claim 1 , wherein the abrasive grains are selected from the group consisting of single diamond particles, poly-crystalline diamond particles, alumina, Si3N4, zirconia, cBN, SiC, and combinations thereof. 
     
     
         19 . The method according to  claim 1 , wherein the metal bond is selected from the group consisting of brazing materials, metal powder bond materials, and combinations thereof. 
     
     
         20 . The method according to  claim 1 , wherein the low CTE substrate is selected from the group consisting of Invar, Super Invar and Kovar and combinations thereof.