Polishing tool and polishing apparatus

Abstract

A polishing tool is used for polishing a workpiece ( 13 ) such as a semiconductor wafer to a flat mirror finish. The polishing tool has a polishing table ( 10 ) and a polishing pad ( 11 ) attached to an upper surface of the polishing table ( 10 ). The polishing pad ( 11 ) has a plurality of polishing pad pieces ( 111 ) attached to the polishing table ( 10 ). It is possible to facilitate adjustment of polishing performance over a surface of the workpiece ( 13 ) and replacement of a polishing pad ( 10 ).

1 . A polishing tool for polishing a workpiece, said polishing tool comprising: 
 a polishing table; and    a polishing pad attached to an upper surface of said polishing table, said polishing pad having a plurality of polishing pad pieces attached to said polishing table.    
     
     
         2 . The polishing tool as recited in  claim 1 , wherein said polishing table has a plurality of recesses for receiving said plurality of polishing pad pieces.  
     
     
         3 . The polishing tool as recited in  claim 2 , wherein said plurality of recesses has the same shape as said plurality of polishing pad pieces.  
     
     
         4 . The polishing tool as recited in  claim 1 , wherein said polishing table includes a holding plate having a plurality of through-holes for receiving said plurality of polishing pad pieces.  
     
     
         5 . The polishing tool as recited in  claim 4 , wherein said plurality of through-holes has the same shape as said plurality of polishing pad pieces.  
     
     
         6 . The polishing tool as recited in  claim 1 , wherein at least one of said polishing pad pieces is attached to said polishing table by a thermo-sensitive adhesive which is softened and lowered in adhesive strength under a high temperature while it is hardened and increased in adhesive strength under a room temperature.  
     
     
         7 . The polishing tool as recited in  claim 6 , wherein the thermo-sensitive adhesive comprises a liquid crystal material or a hot-melt adhesive.  
     
     
         8 . The polishing tool as recited in  claim 6 , wherein said polishing table has a rough surface onto which the thermo-sensitive adhesive is applied.  
     
     
         9 . A polishing tool for polishing a workpiece, said polishing tool comprising: 
 a polishing table;    a plurality of pedestals attached to an upper surface of said polishing table; and    a polishing pad having a plurality of polishing pad pieces attached to said plurality of pedestals.    
     
     
         10 . The polishing tool as recited in  claim 9 , wherein said polishing table has a plurality of recesses for receiving said plurality of pedestals.  
     
     
         11 . The polishing tool as recited in  claim 10 , wherein said plurality of recesses has the same shape as said plurality of pedestals.  
     
     
         12 . The polishing tool as recited in  claim 9 , wherein said polishing table includes a holding plate having a plurality of through-holes for receiving said plurality of pedestals.  
     
     
         13 . The polishing tool as recited in  claim 12 , wherein said plurality of through-holes has the same shape as said plurality of pedestals.  
     
     
         14 . The polishing tool as recited in  claim 9 , wherein at least one of said pedestals is attached to said polishing table by a thermo-sensitive adhesive which is softened and lowered in adhesive strength under a high temperature while it is hardened and increased in adhesive strength under a room temperature.  
     
     
         15 . The polishing tool as recited in  claim 14 , wherein the thermo-sensitive adhesive comprises a liquid crystal material or a hot-melt adhesive.  
     
     
         16 . The polishing tool as recited in  claim 14 , wherein said plurality of pedestals has a rough surface onto which the thermo-sensitive adhesive is applied.  
     
     
         17 . The polishing tool as recited in  claim 9 , wherein said plurality of pedestals is attached to said polishing table by vacuum attraction.  
     
     
         18 . The polishing tool as recited in  claim 9 , wherein said polishing table is made of a material having a high thermal conductivity, 
 wherein said plurality of pedestals is made of a material having a low thermal conductivity.    
     
     
         19 . The polishing tool as recited in  claim 1 , wherein said polishing pad pieces are arranged so as to form gaps between adjacent polishing pad pieces.  
     
     
         20 . The polishing tool as recited in  claim 19 , further comprising at least one weir disposed in said gaps.  
     
     
         21 . The polishing tool as recited in  claim 1 , wherein each of said polishing pad pieces has a size smaller than the workpiece.  
     
     
         22 . The polishing tool as recited in  claim 1 , wherein said polishing pad pieces have the same material properties and surface shape.  
     
     
         23 . The polishing tool as recited in  claim 1 , wherein said plurality of polishing pad pieces comprises: 
 at least one first polishing pad piece; and    at least one second polishing pad piece having different material properties or surface shape than material properties or surface shape of said at least one first polishing pad piece.    
     
     
         24 . A method of polishing a workpiece, said method comprising: 
 pressing the workpiece against the polishing tool as recited in  claim 1;     supplying a polishing liquid to an upper surface of the polishing tool; and    moving the polishing tool and the workpiece relative to each other to polish the workpiece.    
     
     
         25 . A method of attaching a polishing pad to a polishing table, said method comprising: 
 applying a thermo-sensitive adhesive between the polishing table and the polishing pad, the thermo-sensitive adhesive being softened and lowered in adhesive strength under a high temperature while being hardened and increased in adhesive strength under a room temperature;    heating the thermo-sensitive adhesive when the polishing pad is disposed on the polishing table; and    cooling the thermo-sensitive adhesive after said heating to bond the polishing pad to the polishing table.    
     
     
         26 . The method as recited in  claim 25 , wherein the polishing pad has a plurality of polishing pad pieces attached to the polishing table.  
     
     
         27 . The method as recited in  claim 25 , wherein said heating comprising introducing a heating medium adjusted in temperature into the polishing table.  
     
     
         28 . The method as recited in  claim 25 , wherein said cooling comprising introducing a cooling medium adjusted in temperature into the polishing table.  
     
     
         29 . The method as recited in  claim 25 , wherein said heating comprising heating the thermo-sensitive adhesive by a heating device provided near an unbonded surface of the polishing pad.  
     
     
         30 . The method as recited in  claim 25 , wherein said cooling comprising cooling the thermo-sensitive adhesive by a cooling device provided near an unbonded surface of the polishing pad.  
     
     
         31 . A polishing apparatus for polishing a workpiece, said polishing apparatus comprising: 
 a polishing table;    a polishing pad attached to an upper surface of said polishing table, said polishing pad having a plurality of polishing pad pieces attached to said polishing table;    a top ring for pressing the workpiece against said polishing pad;    a light source provided in said polishing table for emitting light to a surface of the workpiece through an opening formed between adjacent polishing pad pieces; and    a light-receiving portion provided in said polishing table for receiving light reflected from the workpiece.    
     
     
         32 . A polishing apparatus for polishing a workpiece, said polishing apparatus comprising: 
 a polishing table;    a plurality of pedestals attached to an upper surface of said polishing table;    a polishing pad having a plurality of polishing pad pieces attached to said plurality of pedestals;    a top ring for pressing the workpiece against said polishing pad;    a light source provided in said polishing table for emitting light to a surface of the workpiece through an opening formed between adjacent polishing pad pieces; and    a light-receiving portion provided in said polishing table for receiving light reflected from the workpiece.    
     
     
         33 . A polishing apparatus for polishing a workpiece, said polishing apparatus comprising: 
 a polishing table;    a polishing pad attached to an upper surface of said polishing table, said polishing pad having at least one light-transmissive piece and a plurality of polishing pad pieces attached to said polishing table;    a top ring for pressing the workpiece against said polishing pad;    a light source provided in said polishing table for emitting light to a surface of the workpiece through said at least one light-transmissive piece; and    a light-receiving portion provided in said polishing table for receiving light reflected from the workpiece.    
     
     
         34 . A polishing apparatus for polishing a workpiece, said polishing apparatus comprising: 
 a polishing table;    a plurality of pedestals attached to an upper surface of said polishing table;    a polishing pad having at least one light-transmissive piece and a plurality of polishing pad pieces attached to said plurality of pedestals;    a top ring for pressing the workpiece against said polishing pad;    a light source provided in said polishing table for emitting light to a surface of the workpiece through said at least one light-transmissive piece; and    a light-receiving portion provided in said polishing table for receiving light reflected from the workpiece.    
     
     
         35 . A polishing apparatus for polishing a workpiece, said polishing apparatus comprising: 
 a polishing table;    a polishing pad attached to an upper surface of said polishing table, said polishing pad having a plurality of polishing pad pieces attached to said polishing table;    a top ring for pressing the workpiece against said polishing pad;    a light source provided in said polishing table for emitting light to a surface of the workpiece through at least one through-hole formed in at least one of said plurality of polishing pad pieces;    a light-receiving portion provided in said polishing table for receiving light reflected from the workpiece;    a fluid supply passage aligned with said at least one through-hole for supplying measurement fluid; and    a fluid discharge passage aligned with said at least one through-hole for discharging the measurement fluid.    
     
     
         36 . A polishing apparatus for polishing a workpiece, said polishing apparatus comprising: 
 a polishing table;    a plurality of pedestals attached to an upper surface of said polishing table;    a polishing pad having a plurality of polishing pad pieces attached to said plurality of pedestals;    a top ring for pressing the workpiece against said polishing pad;    a light source provided in said polishing table for emitting light to a surface of the workpiece through at least one through-hole formed in at least one of said plurality of polishing pad pieces and at least one through-hole formed in at least one of said plurality of pedestals;    a light-receiving portion provided in said polishing table for receiving light reflected from the workpiece;    a fluid supply passage for supplying measurement fluid, said fluid supply passage being aligned with said at least one through-hole formed in said at least one of said plurality of polishing pad pieces and said at least one through-hole formed in said at least one of said plurality of pedestals; and    a fluid discharge passage for discharging the measurement fluid, said fluid discharge passage being aligned with said at least one through-hole formed in said at least one of said plurality of polishing pad pieces and said at least one through-hole formed in said at least one of said plurality of pedestals.    
     
     
         37 . A polishing apparatus for polishing a workpiece, said polishing apparatus comprising: 
 a polishing table;    a polishing pad attached to an upper surface of said polishing table, said polishing pad including: 
 a groove in said upper surface of said polishing pad for allowing a polishing liquid to pass therethrough; and  
 a weir provided in said groove to disturb flow of the polishing liquid; and  
   a top ring for pressing the workpiece against said polishing pad.    
     
     
         38 . A polishing apparatus for polishing a workpiece, said polishing apparatus comprising: 
 a polishing table;    a polishing pad bonded to an upper surface of said polishing table by an adhesive made of a liquid crystal material; and    a top ring for pressing the workpiece against said polishing pad.