Method for polishing workpiece, polishing apparatus and method for manufacturing semiconductor device

Abstract

A region free of groove is provided in a central portion of a polishing pad, and a region having grooves formed thereon is provided on the outer portion thereof. A retainer ring surrounds and sustains a circumference portion of the wafer, and a part that tends to provide higher polishing rate, which is adjacent to the retainer ring in the circumference portion, is disposed so as to face against the region free of the groove. Then, while pressing the wafer against the polishing pad, these are rotated in the same direction. Then, a slurry is supplied from a slurry feeding unit to the outer portion of the region free of groove. Since substantially no slurry is supplied in the region free of groove, the polishing rate is reduced there, and thus a uniform polishing rate over the entire wafer is provided.

1 . A method for polishing a workpiece, comprising: 
 providing a compressible contact between a principal surface of a polishing pad and a polishing surface of a workpiece;    continuously moving a relative position of said polishing pad with said workpiece while the condition of being in compressible contact between said principal surface of said polishing pad and said polishing surface of said workpiece is maintained; and    supplying an abrasive material between said polishing pad and said workpiece,    wherein quantity of said abrasive material contacting said workpiece has a distribution profile over a region where the principal surface of said polishing pad is in contact with the polishing surface of said workpiece.    
     
     
         2 . The method according to  claim 1 , wherein said abrasive material has a distribution profile over said polishing pad.  
     
     
         3 . The method according to  claim 2 , wherein said polishing pad is rotated around a central axis, and said workpiece is oscillated on a region where said abrasive material has a distribution profile.  
     
     
         4 . The method according to  claim 3 , wherein, on said polishing pad, quantity of said abrasive material is lower in a location that is closer to the center than a position where said abrasive material is dropped, and quantity of said abrasive material is higher in a location that is closer to the outer circumference than said position.  
     
     
         5 . The method according to  claim 3 , wherein said polishing pad is provided with grooves formed thereon, 
 and wherein, on said polishing pad, quantity of said abrasive material is lower in a region where density of said grooves is lower, and quantity of said abrasive material is higher in a region where density of said grooves is higher.    
     
     
         6 . The method according to  claim 5 , wherein density of said grooves is lower in a central region of said polishing pad, and density of said grooves is higher in a circumference region thereof.  
     
     
         7 . The method according to  claim 5 , wherein said central region of said polishing pad is free of said groove.  
     
     
         8 . The method according to  claim 3 , wherein said polishing pad is provided with grooves formed therein, 
 and wherein, on said polishing pad, quantity of said abrasive material is lower in a region where a width of a concave portion in said groove is narrower, and quantity of said abrasive material is higher in a region where a width of a concave portion in said groove is wider.    
     
     
         9 . The method according to  claim 8 , wherein a width of a concave portion in said groove is narrower in a central region of said polishing pad, and a width of a concave portion in said groove is wider in a circumference region of said polishing pad.  
     
     
         10 . The method according to  claim 1 , further comprising: 
 providing a compressible contact between a principal surface of said polishing pad and a polishing surface of said workpiece, so that at least a portion on the polishing surface of said workpiece, which tends to provide higher polishing rate, is located in a region on the principal surface of said polishing pad, which contains less quantity of said abrasive material.    
     
     
         11 . The method according to  claim 10 , wherein a ring-type retainer surrounds a circumference portion of said workpiece to sustain said workpiece, and 
 wherein said portion on the polishing surface of said workpiece, which tends to provide higher polishing rate, is a portion of said circumference portion being adjacent to said ring-type retainer.    
     
     
         12 . A method of polishing a workpiece, comprising: 
 providing a compressible contact between a principal surface of a polishing pad and a polishing surface of a workpiece;    continuously moving a relative position of said polishing pad against said workpiece while the condition of being in compressible contact between said principal surface of said polishing pad and said polishing surface of said workpiece is maintained; and    supplying an abrasive material between said polishing pad and said workpiece,    wherein a circumference portion of said workpiece is sustained with a ring-type retainer, and    wherein said polishing pad is in compressible contact with said workpiece, while said ring-type retainer is disposed so that at least a portion of said ring-type retainer extends beyond an edge of said polishing pad.    
     
     
         13 . A polishing pad for polishing a workpiece by forcing a rotating workpiece to provide a compressible contact between said workpiece and said polishing pad and by supplying abrasive material between said workpiece and said polishing pad while said polishing pad being rotated, 
 wherein said polishing pad is partially provided with grooves formed therein, and    wherein density of said grooves has a distribution profile across a principal surface of said polishing pad, thereby said polishing pad being provided with a first region having lower polishing rate and a second region having higher polishing rate.    
     
     
         14 . The polishing pad according to  claim 13 , wherein the density of said groove on said polishing pad is lower in a region of said polishing pad corresponding to higher polishing rate portion of said workpiece and the density of said groove on said polishing pad is higher in a region of said polishing pad corresponding to lower polishing rate portion of said workpiece.  
     
     
         15 . The polishing pad according to  claim 13 , wherein a width of a concave portion in said groove of said polishing pad is narrower in a region of said polishing pad corresponding to higher polishing rate portion of said workpiece and a width of a concave portion in said groove of said polishing pad is wider in a region of said polishing pad providing lower polishing rate portion of said workpiece.  
     
     
         16 . The polishing pad according to  claim 13 , wherein the density of said grooves is lower in a central region of said polishing pad.  
     
     
         17 . The polishing pad according to  claim 13 , wherein the width of the concave portion in said groove is narrower in a central region of said polishing pad.  
     
     
         18 . The polishing pad according to  claim 13 , wherein the central region of said polishing pad is free of said groove.  
     
     
         19 . The polishing pad according to  claim 13 , wherein said grooves are concentric circular.  
     
     
         20 . A polishing apparatus comprising the polishing pad according to  claim 13 .  
     
     
         21 . The polishing apparatus according to  claim 20 , further comprising: 
 a polishing pad driving unit which rotates said polishing pad;    an abrasive material feeding unit which supplies an abrasive material to a predetermined position on said polishing pad; and    a workpiece driving unit which rotates said workpiece while forcing said workpiece so that said workpiece is in compressible contact with said polishing pad.    
     
     
         22 . The polishing apparatus according to  claim 21 , wherein said polishing pad driving unit and said workpiece driving unit comprise a mechanism for providing provides a compressible contact between a principal surface of said polishing pad and a polishing surface of said workpiece so that at least a portion of the polishing surface of said workpiece having tendency to provide higher polishing rate is located in a region containing smaller amount of said abrasive material of a principal surface of said polishing pad.  
     
     
         23 . The polishing apparatus according to  claim 22 , wherein said workpiece driving unit comprises a ring-type retainer for surrounding a circumference portion of said workpiece to sustain said workpiece, and 
 wherein said portion of the polishing surface of said workpiece having tendency to provide higher polishing rate is a portion of a circumference portion being adjacent to said ring-type retainer.    
     
     
         24 . A polishing apparatus, comprising: 
 a polishing pad;    a polishing pad driving unit which rotates said polishing pad; and    a workpiece driving unit which forces said workpiece so that said workpiece compressibly contacts said polishing pad while rotating said workpiece, said workpiece driving unit comprising a ring-type retainer for surrounding a circumference portion of said workpiece to sustain said workpiece, and said workpiece driving unit being capable of sustaining said workpiece thereon so that at least a portion of said ring-type retainer extends beyond an edge of said polishing pad.    
     
     
         25 . A method for manufacturing a semiconductor device, comprising: 
 creating a conducting region within a wafer by utilizing an ion implantation technology;    forming an insulating layer and/or a conducting layer by utilizing a deposition technology, both of said layers composing a portion of said wafer;    processing said wafer into a predetermined shape by utilizing a lithography technology; and    recognizing said wafer as a workpiece and conducting the method for polishing the workpiece according to claims  1 .    
     
     
         26 . A method for manufacturing a semiconductor device, comprising: 
 forming an insulating film on the semiconductor substrate; and    polishing a surface of said insulating film to planarize the surface of said insulating film,    wherein said polishing is conducted by utilizing said method for polishing the workpiece according to claims  1 .    
     
     
         27 . A method for manufacturing a semiconductor device, comprising: 
 forming an insulating film on the semiconductor substrate;    forming a groove on said insulating film;    forming a conducting film within said groove and on said insulating film; and    polishing at least a portion of said conducting film formed on said insulating film to planarizing a surface composed of the surface of said insulating film and the surface of said conducting film,    wherein said polishing is conducted by utilizing said method for polishing the workpiece according to claims  1 .