Dummy disk, dressing disk, and surface height measurement method using dummy disk

Abstract

Provided is a dummy disk which enables a surface height measurement instrument to accurately measure heights of a table surface of a polishing table. A dummy disk is fixed to a disk holder of a dresser when heights of a table surface of a polishing table are measured. The dummy disk includes a first surface capable of coming into contact with the disk holder and a second surface which is on an opposite side of the first surface. The second surface has a plurality of liquid discharge channels, and the plurality of liquid discharge channels extends from one end of the second surface to the other end.

What is claimed is: 
     
         1 . A dummy disk fixed to a disk holder of a dresser when heights of a table surface of a polishing table are measured, comprising:
 a first surface capable of coming into contact with the disk holder; and   a second surface which is on an opposite side of the first surface,   wherein the second surface has a plurality of liquid discharge channels, and   the plurality of liquid discharge channels extends from one end of the second surface to the other end.   
     
     
         2 . The dummy disk according to  claim 1 , wherein the plurality of liquid discharge channels is a plurality of grooves. 
     
     
         3 . The dummy disk according to  claim 2 , wherein the plurality of grooves is a plurality of straight grooves arranged in parallel to each other. 
     
     
         4 . The dummy disk according to  claim 1 , wherein the plurality of liquid discharge channels is a plurality of first grooves and a plurality of second grooves intersecting the plurality of first grooves. 
     
     
         5 . The dummy disk according to  claim 4 , wherein the plurality of second grooves is perpendicular to the plurality of first grooves. 
     
     
         6 . The dummy disk according to  claim 1 , wherein the plurality of liquid discharge channels is uniformly distributed over the entire second surface. 
     
     
         7 . The dummy disk according to  claim 1 , wherein an area of the plurality of liquid discharge channels occupies 40%-81% of an area of the entire second surface. 
     
     
         8 . A dressing disk fixed to a disk holder of a dresser when a polishing surface of a polishing pad is dressed, comprising:
 a first surface capable of coming into contact with the disk holder; and   a second surface which is on an opposite side of the first surface,   wherein the second surface has a plurality of protrusion portions and a plurality of liquid discharge channels positioned between the plurality of protrusion portions,   the plurality of liquid discharge channels extends from one end of the second surface to the other end, and   abrasive grains are fixed to surfaces of the plurality of protrusion portions.   
     
     
         9 . The dressing disk according to  claim 8 , wherein the plurality of liquid discharge channels is a plurality of grooves. 
     
     
         10 . The dressing disk according to  claim 9 , wherein the plurality of grooves is a plurality of straight grooves arranged in parallel to each other. 
     
     
         11 . The dressing disk according to  claim 8 , wherein the plurality of liquid discharge channels is a plurality of first grooves and a plurality of second grooves intersecting the plurality of first grooves. 
     
     
         12 . The dressing disk according to  claim 11 , wherein the plurality of second grooves is perpendicular to the plurality of first grooves. 
     
     
         13 . The dressing disk according to  claim 8 , wherein the plurality of liquid discharge channels is uniformly distributed on the entire second surface. 
     
     
         14 . The dressing disk according to  claim 8 , wherein an area of the liquid discharge channels occupies 40%-81% of an area of the entire second surface. 
     
     
         15 . A method, comprising
 making a polishing table and a dummy disk rotate;   bringing the dummy disk into contact with a table surface of the polishing table while a liquid is supplied to the table surface;   measuring heights of the table surface at a plurality of measurement points while the dummy disk is moved on the table surface; and   creating a table profile showing tilt of the table surface from measurement values of the heights of the table surface,   wherein the dummy disk is the dummy disk according to  claim 1 .   
     
     
         16 . The method according to  claim 15 , further comprising: calculating a tilt angle of the table profile from a horizontal line; and
 correcting the table profile by rotating the table profile until the tilt angle is 0.   
     
     
         17 . The method according to  claim 16 , further comprising:
 rotating a polishing pad arranged on the table surface along with the polishing table, and rotating a dressing disk;   bringing the dressing disk into contact with a polishing surface of the polishing pad while a liquid is supplied to the polishing surface;   measuring heights of the polishing surface at a plurality of measurement points while the dressing disk is moved on the polishing surface; and   creating an initial pad profile showing a height distribution of the polishing surface from measurement values of the heights of the polishing surface,   wherein the dressing disk is fixed to a disk holder of a dresser when a polishing surface of a polishing pad is dressed, and the dressing disk comprises:   a first surface capable of coming into contact with the disk holder; and   a second surface which is on an opposite side of the first surface,   wherein the second surface has a plurality of protrusion portions and a plurality of liquid discharge channels positioned between the plurality of protrusion portions,   the plurality of liquid discharge channels extends from one end of the second surface to the other end, and   abrasive grains are fixed to surfaces of the plurality of protrusion portions.   
     
     
         18 . The method according to  claim 17 , further comprising:
 correcting the initial pad profile by rotating the initial pad profile by an angle the same as the tilt angle, wherein a direction in which the initial pad profile is rotated is the same as a direction in which the table profile is rotated.   
     
     
         19 . The method according to  claim 18 , further comprising:
 displaying the corrected table profile and the corrected initial pad profile on a display screen.   
     
     
         20 . The method according to  claim 16 , wherein the polishing table, the table surface, and the table profile are respectively a first polishing table, a first table surface, and a first table profile, and
 the method further comprises:   rotating a second polishing table and the dummy disk;   bringing the dummy disk into contact with a second table surface of the second polishing table while a liquid is supplied to the second table surface;   measuring heights of the second table surface at a plurality of measurement points while the dummy disk is moved on the second table surface;   creating a second table profile showing tilt of the second table surface from measurement values of the heights of the second table surface;   calculating a tilt angle of the second table profile from the horizontal line; and   correcting the second table profile by rotating the second table profile until the tilt angle of the second table profile is 0.