Methods and apparatus for polishing an edge of a substrate

Abstract

Methods, systems and apparatus are provided for polishing an edge of a substrate. The invention includes an apparatus adapted to apply a preset pressure to a polishing film in contact with an edge of a substrate. The apparatus includes an actuator adapted to apply a preset pressure to the polishing film; and a controller coupled to the actuator and adapted to receive a signal indicative of a condition of the edge of the substrate, and to adjust a pressure applied by the actuator to the polishing film so as to maintain the preset pressure based on the received signal. Numerous other aspects are provided.

1 . An apparatus adapted to apply a preset pressure to a polishing film in contact with an edge of a substrate comprising:
 an actuator adapted to apply a preset pressure to the polishing film; and   a controller coupled to the actuator and adapted to receive a signal indicative of a condition of the edge of the substrate, and to adjust a pressure applied by the actuator to the polishing film so as to maintain the preset pressure based on the received signal.   
   
   
       2 . The apparatus of  claim 1  wherein the polishing film is adapted to conform to the edge of the substrate via application of the preset pressure. 
   
   
       3 . The apparatus of  claim 1 , wherein the signal indicates whether an endpoint has been reached. 
   
   
       4 . The apparatus of  claim 1 , wherein the signal indicates whether a layer of material has been removed from the edge of the substrate. 
   
   
       5 . The apparatus of  claim 1 , wherein the signal indicates whether an intended edge profile has been reached. 
   
   
       6 . The apparatus as recited in  claim 1 , further comprising:
 a driver coupled to the controller adapted to rotate the substrate against the polishing film, the driver adapted to generate a signal indicative of the condition of the edge of the substrate.   
   
   
       7 . The apparatus of  claim 6 , wherein the controller is coupled to and adapted to direct operation of the driver in response to a signal received from the at least one sensor so as to attain a preset polish level. 
   
   
       8 . The apparatus of  claim 1  further comprising a friction sensor coupled to the controller and adapted to provide a signal indicative of an amount of friction between the substrate and the polishing film. 
   
   
       9 . The apparatus of  claim 8  wherein the amount of friction between the substrate and the polishing film is indicative of an amount of material that has been removed from the substrate. 
   
   
       10 . The apparatus of  claim 6  wherein the signal indicates an amount of force applied to the actuator to push the polishing film against the substrate. 
   
   
       11 . The apparatus of  claim 6  wherein the signal indicates an amount of energy being exerted to drive the substrate. 
   
   
       12 . The apparatus of  claim 1  wherein the actuator further comprises a solenoid. 
   
   
       13 . The apparatus of  claim 12 , wherein the amount of pressure applied by the actuator is determined based on the amount current drawn by the solenoid. 
   
   
       14 . The apparatus of  claim 1  wherein the preset pressure is at least one of constant or varied. 
   
   
       15 . The apparatus of  claim 1  further comprising a head adapted to support the polishing film. 
   
   
       16 . The apparatus of  claim 15  further comprising a pad mounted to the head via the actuator, and adapted to press the polishing film against the substrate. 
   
   
       17 . The apparatus of  claim 16 , wherein the pad is adapted to contour the polishing film to an edge of the substrate. 
   
   
       18 . The apparatus of  claim 15  wherein the actuator is adapted to push the head towards the substrate. 
   
   
       19 . The apparatus of  claim 16  further comprising a fluid supply coupled to the controller, wherein a fluid is delivered to the substrate via the pad. 
   
   
       20 . The apparatus of  claim 19  further comprising one or more fluid channels, wherein the fluid channels are adapted to deliver the fluid to the pad.