Wafer polishing with counteraction of centrifugal forces on polishing slurry

Abstract

Polishing slurry consumption in the wafer polishing process can be reduced by using a polishing pad structure that directs portions of the slurry flow towards the center of the polishing pad.

What is claimed is:  
     
         1 . An apparatus for polishing a wafer used to manufacture integrated circuits, comprising: 
 a pad body having a polishing surface; and    said polishing surface having formed therein a groove, said groove defining a continuous edge which extends continuously from a first location adjacent an outer peripheral edge of said polishing surface to a second location adjacent a central point of said polishing surface, said continuous edge extending across a majority of a distance between said outer peripheral edge and said central point.    
     
     
         2 . The apparatus of  claim 1 , wherein said continuous edge of said groove directs slurry toward said central point of said polishing surface when said pad body is rotated relative to the wafer in a predetermined direction to polish the wafer.  
     
     
         3 . The apparatus of  claim 2 , wherein said continuous edge opens concavely toward said predetermined direction.  
     
     
         4 . The apparatus of  claim 2 , wherein said continuous edge spirals around said central point of said polishing surface.  
     
     
         5 . The apparatus of  claim 1 , wherein said continuous edge extends continuously from said outer peripheral edge of said polishing surface to said central point of said polishing surface.  
     
     
         6 . The apparatus  claim 5 , wherein said continuous edge has a generally curved configuration.  
     
     
         7 . The apparatus of  claim 5 , wherein said continuous edge spirals around said central point of said polishing surface.  
     
     
         8 . The apparatus of  claim 1 , wherein said continuous edge has a generally curved configuration.  
     
     
         9 . The apparatus of  claim 8 , wherein said groove increases in depth from said second location toward said first location.  
     
     
         10 . The apparatus of  claim 1 , wherein said continuous edge spirals around said central point of said polishing surface.  
     
     
         11 . The apparatus of  claim 10 , wherein said groove increases in depth from said second location toward said first location.  
     
     
         12 . The apparatus of  claim 1 , wherein said groove increases in depth from said second location toward said first location.  
     
     
         13 . The apparatus of  claim 1 , wherein said polishing surface includes a plurality of said grooves defining a respectively corresponding plurality of said continuous edges.  
     
     
         14 . The apparatus of  claim 13 , wherein said plurality of grooves cover a majority of said polishing surface.  
     
     
         15 . The apparatus of  claim 13 , wherein each of said continuous edges directs slurry toward said central point of said polishing surface when said pad body is rotated relative to the wafer in a predetermined direction to polish the wafer.  
     
     
         16 . The apparatus of  claim 15 , wherein each of said continuous edges opens concavely toward said predetermined direction.  
     
     
         17 . The apparatus of  claim 13 , wherein each of said continuous edges extends from said outer peripheral edge of said polishing surface to said central point of said polishing surface.  
     
     
         18 . An apparatus for polishing a wafer used to manufacture integrated circuits, comprising: 
 a pad body having a polishing surface;    said polishing surface having formed therein a groove, said groove defining a continuous edge which extends continuously from a first location adjacent an outer peripheral edge of said polishing surface to a second location adjacent a central point of said polishing surface, said continuous edge extending across a majority of a distance between said outer peripheral edge and said central point;    a holding apparatus having said pad body mounted thereon; and    said holding apparatus for holding the wafer in contact with said polishing surface of said pad body while effecting relative rotation between the wafer and said pad body.    
     
     
         19 . The apparatus of  claim 18 , wherein said polishing surface includes a plurality of said grooves defining a respectively corresponding plurality of said continuous edges.  
     
     
         20 . The apparatus of  claim 18 , wherein said continuous edge of said groove directs slurry toward said central point of said polishing surface when said pad body is rotated relative to the wafer in a predetermined direction to polish the wafer.  
     
     
         21 . The apparatus of  claim 20 , wherein said continuous edge opens concavely toward said predetermined direction.  
     
     
         22 . The apparatus of  claim 20 , wherein said continuous edge spirals around said central point of said polishing surface.  
     
     
         23 . A method for directing slurry flow while polishing a wafer used to manufacture integrated circuits, comprising: 
 effecting relative rotation between a polishing surface and the wafer; and    during said relative rotation, the polishing surface directing a continuous flow of slurry from a first location adjacent an outer peripheral edge of the polishing surface to a second location adjacent a central point of the polishing surface and across a majority of a distance between said outer peripheral edge and said central point.