Method for dressing polishing pad, method for polishing silicon wafer, method for producing silicon wafer, and device for polishing silicon wafer

Abstract

A method for dressing a polishing pad that enables more even dressing of the polishing pad even when the surface of the rotating plate is curved. This method for dressing a polishing pad performs dressing of the polishing pad by pressing a grindstone of a pad dresser having the grindstone attached thereto against the polishing pad attached to a polishing plate and sliding the grindstone thereon, and uses a pad dresser which is configured to allow a radius of curvature, in the radial direction of the polishing plate, of a dressing surface of the grindstone that slides on the polishing pad to be changed.

1 . A method for dressing a polishing pad performing dressing of the polishing pad by pressing a grindstone of a pad dresser having the grindstone attached thereto against the polishing pad attached to a polishing plate and sliding the grindstone thereon, wherein
 using a pad dresser which is configured to allow a radius of curvature R 1 , in the radial direction of the polishing plate, of a dressing surface of the grindstone that slides on the polishing pad is to be changed.   
     
     
         2 . The method for dressing a polishing pad as claimed in  claim 1 , wherein changing the radius of curvature R 1  of the dressing surface of the grindstone to be smaller than a radius of curvature R 2  of a surface of the polishing pad, and then performing dressing of the polishing pad. 
     
     
         3 . The method for dressing a polishing pad as claimed in  claim 1 , wherein using a pad dresser in which the grindstone has a plurality of dressing surfaces with different radius of curvatures, and the radius of curvature R 2  of the dressing surface that slides on the polishing pad can be changed by rotating the grindstone. 
     
     
         4 . The method for dressing a polishing pad as claimed in  claim 1 , wherein using a pad dresser in which a base material of the grindstone is made of an alloy capable of flexing, and the radius of curvature R 1  of the dressing surface can be changed by pressing the grindstone from an opposite side of the dressing surface. 
     
     
         5 . The method for dressing a polishing pad as claimed in  claim 4 , wherein using a pad dresser in which the grindstone is attached to the pad dresser via a retainer, two ends of the base material of the grindstone are coupled to the retainer, and the radius of curvature R 1  of the dressing surface can be changed by pressing a portion of the grindstone on an opposite side of the dressing surface with a pressing member. 
     
     
         6 . The method for dressing a polishing pad as claimed in  claim 4 , wherein using a pad dresser in which the grindstone is attached to the pad dresser via a retainer that has a different coefficient of thermal expansion than the base material of the grindstone, and the radius of curvature R 1  of the dressing surface can be changed by changing temperature of the retainer. 
     
     
         7 . A method for polishing a silicon wafer, wherein comprising polishing a silicon wafer using a polishing pad that has been dressed using the method for dressing a polishing pad according to  claim 1 . 
     
     
         8 . A method for producing a silicon wafer, wherein comprising polishing a silicon wafer obtained by performing wafer processing treatment on a single crystal silicon ingot grown by a predetermined method, using the method for polishing a silicon wafer according to  claim 7 . 
     
     
         9 . A device for polishing a silicon wafer comprising a polishing plate; a polishing pad attached to the polishing plate; and a pad dresser having a grindstone attached thereto, and dresses the polishing pad, wherein
 the device is configured to allow a radius of curvature R 1 , in the radial direction of the polishing plate, of a dressing surface of the grindstone that slides on the polishing pad to be changed.   
     
     
         10 . A device for polishing a silicon wafer as claimed in  claim 9 , wherein the grindstone has a plurality of dressing surfaces with different radius of curvatures, so that the device is configured to allow the radius of curvature R 1  of the dressing surface that slides on the polishing pad to be changed by rotating the grindstone. 
     
     
         11 . A device for polishing silicon wafer as claimed in  claim 10 , wherein a base material of the grindstone is made of an alloy capable of flexing, so that the device is configured to allow the radius of curvature R 1  of the dressing surface to be changed by pressing the grindstone from an opposite side of the dressing surface. 
     
     
         12 . A device for polishing silicon wafer as claimed in  claim 11 , wherein the grindstone is attached to the pad dresser via a retainer and two ends of the base material of the grindstone are coupled to the retainer, so that the device is configured to allow the radius of curvature R 1  of the dressing surface to be changed by pressing a portion of the grindstone on an opposite side of the dressing surface with a pressing member. 
     
     
         13 . A device for polishing a silicon wafer as claimed in  claim 11 , wherein the grindstone is attached to the pad dresser via a retainer that has a different coefficient of thermal expansion than the base material of the grindstone, so that the device is configured to allow the radius of curvature R 1  of the dressing surface to be changed by changing temperature of the retainer. 
     
     
         14 . The method for dressing a polishing pad as claimed in  claim 2 , wherein using a pad dresser in which the grindstone has a plurality of dressing surfaces with different radius of curvatures, and the radius of curvature R 2  of the dressing surface that slides on the polishing pad can be changed by rotating the grindstone. 
     
     
         15 . The method for dressing a polishing pad as claimed in  claim 2 , wherein using a pad dresser in which a base material of the grindstone is made of an alloy capable of flexing, and the radius of curvature R 1  of the dressing surface can be changed by pressing the grindstone from an opposite side of the dressing surface. 
     
     
         16 . The method for dressing a polishing pad as claimed in  claim 14 , wherein using a pad dresser in which the grindstone is attached to the pad dresser via a retainer, two ends of the base material of the grindstone are coupled to the retainer, and the radius of curvature R 1  of the dressing surface can be changed by pressing a portion of the grindstone on an opposite side of the dressing surface with a pressing member. 
     
     
         17 . The method for dressing a polishing pad as claimed in  claim 15 , wherein using a pad dresser in which the grindstone is attached to the pad dresser via a retainer that has a different coefficient of thermal expansion than the base material of the grindstone, and the radius of curvature R 1  of the dressing surface can be changed by changing temperature of the retainer. 
     
     
         18 . A method for polishing a silicon wafer, wherein comprising polishing a silicon wafer using a polishing pad that has been dressed using the method for dressing a polishing pad according to  claim 2 . 
     
     
         19 . A method for producing a silicon wafer, wherein comprising polishing a silicon wafer obtained by performing wafer processing treatment on a single crystal silicon ingot grown by a predetermined method, using the method for polishing a silicon wafer according to  claim 18 .