Polishing method for semiconductor wafer and polishing apparatus for semiconductor wafer

Abstract

A polishing method for a semiconductor wafer having a polishing target surface at a periphery portion thereof is disclosed. The method includes pressing a polishing member against the polishing target surface along a circumference of the semiconductor wafer by a plurality of pressing portions while rotating the semiconductor wafer in a circumferential direction, thereby polishing the polishing target surface of the semiconductor wafer.

1 . A polishing method for a semiconductor wafer having a polishing target surface at a periphery portion thereof, the method comprising: 
 pressing a polishing member against the polishing target surface along a circumference of the semiconductor wafer by a plurality of pressing portions while rotating the semiconductor wafer in a circumferential direction, thereby polishing the polishing target surface of the semiconductor wafer.    
   
   
       2 . The method according to  claim 1 , 
 wherein the plurality of pressing portions include a plurality of individually controllable displacement portions.    
   
   
       3 . The method according to  claim 2 , 
 wherein each of the displacement portions has a pressing head which is movable in a direction substantially vertical to a contact region of the polishing member and the polishing target surface.    
   
   
       4 . The method according to  claim 3 , 
 wherein an elastic member is interposed between the pressing heads and the polishing member.    
   
   
       5 . The method according to  claim 2 , 
 wherein each of the displacement portions has a hollow portion whose internal pressure is controllable.    
   
   
       6 . The method according to  claim 2 , 
 wherein a displacement amount of each of the displacement portions is controlled in accordance with a curvature of the polishing target surface.    
   
   
       7 . The method according to  claim 1 , 
 wherein the plurality of pressing portions include a plurality of convex portions.    
   
   
       8 . The method according to  claim 7 , 
 wherein the convex portions have elasticity.    
   
   
       9 . The method according to  claim 8 , 
 wherein the plurality of convex portions are fixed to a base portion that is positioned between the convex portions and the polishing member and has elasticity.    
   
   
       10 . The method according to  claim 7 , 
 wherein at least one of a height, a size, and hardness of each of the convex portions is adjusted in accordance with an arrangement position of each of the convex portions.    
   
   
       11 . The method according to  claim 7 , 
 wherein a distal end of each of the convex portions has a rounded shape.    
   
   
       12 . The method according to  claim 1 , 
 wherein a distribution of a pressure applied to the polishing target surface has a plurality of peaks based on the plurality of pressing portions.    
   
   
       13 . The method according to  claim 12 , 
 wherein heights of the plurality of peaks are substantially equal to each other.    
   
   
       14 . The method according to  claim 1 , 
 wherein the polishing target surface is polished while moving a polishing region of the polishing member in the circumferential direction of the semiconductor wafer.    
   
   
       15 . The method according to  claim 1 , 
 wherein the polishing member is selected from a polishing tape and an abrasive pad.    
   
   
       16 . A polishing apparatus for a semiconductor wafer having a polishing target surface at a periphery portion thereof, comprising: 
 a rotation unit which rotates the semiconductor wafer in a circumferential direction; and    a pressing unit which presses a polishing member against the polishing target surface of the semiconductor wafer which is rotated by the rotation unit to polish the polishing target surface, the pressing unit having a plurality of pressing portions which press the polishing member against the polishing target surface along a circumference of the semiconductor wafer.    
   
   
       17 . The apparatus according to  claim 16 , 
 wherein the plurality of pressing portions include a plurality of individually controllable displacement portions.    
   
   
       18 . The apparatus according to  claim 17 , 
 wherein each of the displacement portions has a pressing head which is movable in a direction substantially vertical to a contact region of the polishing member and the polishing target surface.    
   
   
       19 . The apparatus according to  claim 17 , 
 wherein each of the displacement portions has a hollow portion whose internal pressure is controllable.    
   
   
       20 . The apparatus according to  claim 16 , 
 wherein the plurality of pressing portions include a plurality of convex portions.