Methods and apparatus for polishing an edge of a substrate

Abstract

Methods of and systems for polishing an edge of a substrate are provided. The invention includes a substrate rotation driver adapted to rotate the edge of a substrate against a polishing film; and a first sensor coupled to the rotation driver adapted to detect one of an energy and torque exerted by the substrate rotation driver as it rotates the substrate against the polishing film. Numerous other aspects are provided.

1 . A system adapted to polish an edge of a substrate comprising:
 a substrate rotation driver adapted to rotate the edge of a substrate against a polishing film; and   a first sensor coupled to the rotation driver adapted to detect one of an energy and torque exerted by the substrate rotation driver as it rotates the substrate against the polishing film.   
   
   
       2 . The system of  claim 1 , further comprising:
 a controller coupled to the first sensor and to the substrate rotation driver, adapted to receive from the first sensor a signal indicative of the detected energy or torque exerted by the substrate rotation driver and adapted to transmit control signals to the substrate rotation driver based on the detected energy or torque exerted.   
   
   
       3 . The system of  claim 2 , wherein the controller is adapted to determine an amount of material that has been removed from the substrate based on the received signal. 
   
   
       4 . The system of  claim 3 , wherein the controller is adapted to determine a polishing end point based on the amount of removed material. 
   
   
       5 . The system of  claim 2  wherein the controller is adapted to index a pre-set amount of polishing film. 
   
   
       6 . The system of  claim 1 , further comprising:
 an actuator adapted to press the polishing film against the rotating substrate.   
   
   
       7 . The system of  claim 6 , wherein the actuator is adapted to provide a signal indicative of a force exerted by the actuator in pressing the polishing film against the rotating substrate. 
   
   
       8 . The system of  claim 7 , wherein the controller is coupled to the actuator and is adapted to determine a force for the actuator to apply to the polishing film based on the signal provided by the actuator. 
   
   
       9 . The system of  claim 6 , wherein the actuator is adapted to press the polishing film against the rotating substrate for a period of time ranging from 15 to 150 seconds to obtain a preset level of polish. 
   
   
       10 . The system of  claim 8 , wherein the actuator is adapted to apply a force of about 0.5 pounds to 2.0 pounds to the polishing film to obtain a preset level of polish. 
   
   
       11 . The system of  claim 2 , further comprising:
 a fluid supply coupled to the controller and to the polishing film;   wherein the controller is adapted to direct the fluid supply to deliver fluid onto the polishing film.   
   
   
       12 . The system of  claim 11 , wherein the fluid is supplied to a point of contact between the polishing film and the edge of the substrate. 
   
   
       13 . The system of  claim 12 , wherein the fluid includes megasonic energy and wherein the megasonic energy is applied to the substrate via the fluid. 
   
   
       14 . The system of  claim 6 , further comprising:
 a pad coupled to the actuator and adapted to press the polishing film against the substrate.   
   
   
       15 . The system of  claim 14 , wherein the pad is adapted to contour the polishing film to an edge of the substrate. 
   
   
       16 . The system of  claim 14 , further comprising:
 a fluid supply coupled to the controller, wherein a fluid is delivered to the substrate via the pad.   
   
   
       17 . The system of  claim 16 , further comprising:
 one or more fluid channels, wherein the fluid channels are adapted to deliver the fluid to the pad.   
   
   
       18 . The system of  claim 13  wherein the pad is adapted to pivot about an edge of the substrate. 
   
   
       19 . The system of  claim 2  further comprising a friction sensor coupled to the controller, wherein the friction sensor is adapted to provide a signal indicative of an amount of friction between the substrate and the polishing film. 
   
   
       20 . The system of  claim 19  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.