Methods and apparatus for controlling the size of an edge exclusion zone of a substrate

Abstract

In some embodiments, a method of controlling a width of an edge exclusion zone of a substrate is provided. The method includes determining a range of angles over which to rotate a polishing head; rotating the polishing head over the determined range of angles to achieve a preset width for an edge exclusion zone of the substrate; and polishing an edge of the substrate with the polishing head. Numerous other aspects are provided.

1 . A method of controlling a width of an edge exclusion zone on a substrate comprising:
 determining a range of angles over which to rotate a polishing head;   rotating the polishing head over the determined range of angles to achieve a preset width for an edge exclusion zone of the substrate; and   polishing an edge of the substrate with the polishing head.   
   
   
       2 . The method of  claim 1  further comprising:
 determining whether the preset width of the edge exclusion zone has been achieved; and   adjusting the range of angles over which to rotate the polishing head to achieve the preset width for the edge exclusion zone based on the determination of whether the preset width of the edge exclusion zone has been achieved.   
   
   
       3 . The method of  claim 1  further comprising:
 applying a polishing tape to the substrate via the polishing head during polishing to achieve the preset width of the edge exclusion zone.   
   
   
       4 . The method of  claim 1  further comprising:
 operating the polishing head via a controller.   
   
   
       5 . The method of  claim 1  wherein the polishing head includes a backing roller. 
   
   
       6 . The method of  claim 5  further comprising:
 pressing the backing roller against a polishing tape to contact the substrate.   
   
   
       7 . The method of  claim 2  further comprising:
 measuring an actual edge exclusion width to determine whether the preset width of the edge exclusion zone has been achieved.   
   
   
       8 . The method of  claim 7  further comprising:
 comparing the actual edge exclusion width to the preset edge exclusion width to determine whether the preset width of the edge exclusion zone has been achieved.   
   
   
       9 . The method of  claim 7 , further comprising measuring the actual edge exclusion width via one or more sensors. 
   
   
       10 . A method of controlling a width of an edge exclusion zone on a substrate comprising:
 determining a radial position at which to place a polishing head with respect to a substrate so as to achieve a preset width of an edge exclusion zone for the substrate;   moving the polishing head to the determined radial position; and   polishing the substrate with the polishing head.   
   
   
       11 . The method of  claim 10  further comprising:
 determining whether the preset width of the edge exclusion zone has been achieved; and   adjusting the radial position of the polishing head to achieve the preset width of the edge exclusion zone based on the determination of whether the preset width of the edge exclusion zone has been achieved.   
   
   
       12 . The method of  claim 10  further comprising:
 rotating the polishing head when the polishing head is in contact with the substrate.   
   
   
       13 . The method of  claim 12  further comprising:
 applying a polishing tape to the substrate via the rotating polishing head to achieve the preset width of the edge exclusion zone.   
   
   
       14 . A method of controlling a width of an edge exclusion zone on a substrate comprising:
 providing a polishing head having a head spacer and a backing roller coupled to the head spacer at an off-center position and adapted to apply a polishing tape to a substrate during polishing; and   applying the polishing tape to an edge exclusion zone of the substrate using the polishing head during polishing.   
   
   
       15 . The method of  claim 14  further comprising:
 determining whether a preset width of the edge exclusion zone has been attained; and   adjusting at least one of a range of angles over which to rotate the polishing head and a radial position of the polishing head based on the determination of whether the preset width of the edge exclusion zone has been attained.   
   
   
       16 . The method of  claim 14  further comprising:
 operating the polishing head via a controller.   
   
   
       17 . The method of  claim 15  further comprising:
 measuring an actual edge exclusion width to determine whether the preset width of the edge exclusion zone has been attained.   
   
   
       18 . A system for controlling a width of an edge exclusion zone on a substrate comprising:
 a polishing head having a head spacer, wherein the polishing head is adapted to contact an edge of a substrate;   a backing pad coupled to the head spacer at an off-center position;   a polishing arm coupled to the polishing head; and   a controller adapted to operate the polishing head and polishing arm to control an edge exclusion zone of the substrate.   
   
   
       19 . The system of  claim 18  further comprising a polishing tape, wherein the polishing head is adapted to press the polishing tape against the edge of the substrate. 
   
   
       20 . The system of  claim 18  wherein the polishing head is adapted to angularly translate at different angles about the edge of the substrate. 
   
   
       21 . The system of  claim 18  wherein the polishing arm is adapted to move to accommodate exclusion zones with different widths. 
   
   
       22 . The system of  claim 18  wherein the backing roller is adapted to apply a polishing tape to the substrate edge during polishing.