Methods and apparatus for polishing an edge of a substrate

Abstract

Methods for polishing an edge of a substrate are provided. The invention includes rotating a substrate against a polishing film so as to remove material from the edge of the substrate; and detecting an amount of force exerted in pressing the polishing film against the substrate. Numerous other aspects are provided.

1 . A method of polishing an edge of a substrate comprising:
 rotating a substrate against a polishing film so as to remove material from the edge of the substrate; and   detecting an amount of force exerted in pressing the polishing film against the substrate.   
   
   
       2 . The method of  claim 1 , further comprising:
 determining an amount of material removed from the edge of the substrate based on the detected force exerted in pressing the polishing film against the rotating substrate.   
   
   
       3 . The method of  claim 2 , further comprising:
 determining a polishing end point has been reached.   
   
   
       4 . The method of  claim 2 , further comprising:
 determining whether an intended edge profile has been reached.   
   
   
       5 . The method of  claim 2 , further comprising:
 ascertaining a difference between the determined amount of material removed and a preset polish level.   
   
   
       6 . The method of  claim 5 , further comprising:
 determining a level of force to be applied to the polishing film adapted to attain the preset polish level based on the difference between the determined amount of material removed and the preset polish level.   
   
   
       7 . The method of  claim 6 , further comprising:
 adjusting the force to the determined level.   
   
   
       8 . The method of  claim 5 , further comprising:
 ascertaining from the amount of material that has been removed from the substrate edge whether a layer of material has been removed.   
   
   
       9 . The method of  claim 8 , further comprising:
 reducing a rotation speed of the substrate if the removed layer is an endpoint.   
   
   
       10 . The method of  claim 1 , further comprising:
 reducing friction between the substrate and the polishing film by delivering a fluid to the polishing film.   
   
   
       11 . The method of  claim 1 , further comprising:
 removing particles from the edge of the substrate by delivering a fluid to the polishing film during contact with the substrate.   
   
   
       12 . The method of  claim 11 , wherein delivering a fluid further comprises:
 spraying the fluid onto the substrate.   
   
   
       13 . The method of  claim 1 , wherein detecting the amount of exerted force further comprises:
 receiving a feedback signal from at least one of a driver and an actuator.   
   
   
       14 . The method of  claim 1 , further comprising:
 rotating the substrate against the polishing film for about 15 to 150 seconds.   
   
   
       15 . The method of  claim 1 , further comprising:
 rotating the substrate at a rate ranging between 50 and 300 RPMs.   
   
   
       16 . The method of  claim 1 , further comprising:
 angularly translating the polishing film against the substrate.   
   
   
       17 . The method of  claim 1 , further comprising:
 advancing the polishing film as the polishing film contacts the substrate.   
   
   
       18 . The method of  claim 1 , further comprising:
 contouring the polishing film to an edge of the substrate.   
   
   
       19 . The method of  claim 1 , further comprising:
 monitoring a polishing process.   
   
   
       20 . The method of  claim 1 , wherein detecting the amount of force further comprises:
 detecting an amount of current drawn to apply the force.