Method of identifying and tracking roll to roll polishing pad materials during processing

Abstract

Implementations described herein generally relate to methods and apparatus for polishing substrates, more particularly, to methods and apparatus for identifying and/or tracking polishing material in a roll-to-roll polishing system. In one implementation, a method of polishing a substrate is provided. The method comprises advancing a polishing material across a surface of a platen. The polishing material has a polishing surface and an opposing backside surface and the backside surface has a pattern of identifying features formed thereon. The method further comprises sensing the movement of the pattern of identifying features past a detector assembly. The method further comprises controlling a position of the polishing material relative to the platen based on data received from the sensed movement of the pattern of identifying features.

1 . An apparatus for polishing a substrate, comprising:
 a polishing module, comprising:
 a platen for supporting a polishing material having a polishing surface and an opposing backside surface, wherein the backside surface has a plurality of identifying features formed thereon; 
 a supply assembly adapted to provide the polishing material to the platen; and 
 a take-up assembly adapted to receive the polishing material transferred across at least a portion of the platen from the supply assembly; 
   one or more detector assemblies disposed adjacent to the backside surface of the polishing material, wherein the one or more detector assemblies are positioned to sense a change in position of the plurality of identifying features formed on the backside surface as the polishing material is transferred between the supply assembly and the take-up assembly; and   a system controller adapted to receive a signal from the one or more detector assemblies and control the position of the polishing material relative to the platen using an actuator coupled to at least one of the supply assembly and the take-up assembly.   
     
     
         2 . The apparatus of  claim 1 , wherein each of the one or more detector assemblies further comprise:
 an electromagnetic radiation source mounted proximate to the backside surface of the polishing material and adapted to emit electromagnetic radiation; and   a detector mounted proximate to the backside surface of the polishing material and adapted to detect the variation of intensity of the electromagnetic radiation delivered from the electromagnetic radiation source after interacting with the plurality of identifying features formed on the backside surface.   
     
     
         3 . The apparatus of  claim 1 , wherein each of the one or more detector assemblies further comprise:
 an electromagnetic radiation source mounted proximate to the backside surface of the polishing material and adapted to emit electromagnetic radiation; and   a detector mounted proximate to the polishing surface of the polishing material opposite the electromagnetic radiation source and adapted to detect the variation of intensity of the electromagnetic radiation delivered from the electromagnetic radiation source after interacting with the plurality of identifying features formed on the backside surface.   
     
     
         4 . The apparatus for  claim 1 , wherein the polishing material is a continuous sheet of material that has one end coupled with the supply assembly and a second end coupled with the take-up assembly. 
     
     
         5 . The apparatus of  claim 1 , wherein the plurality of identifying features includes regularly spaced regions of deposited material or holes within the polishing material. 
     
     
         6 . The apparatus of  claim 1 , wherein the plurality of identifying features includes a first start of line feature, which identifies a start of a first polishing region of polishing material, and a second start of line feature, which identifies an end of the first polishing region and a start of a second polishing region of polishing material. 
     
     
         7 . The apparatus of  claim 6 , wherein the first polishing region of polishing material and the second polishing region of polishing material have similar or substantially similar patterns of polishing features. 
     
     
         8 . The apparatus of  claim 1 , wherein each of the one or more detector assemblies comprise a capacitive type sensor, an optical measurement sensor, or an eddy current measurement sensor. 
     
     
         9 . The apparatus of  claim 1 , wherein the polishing material, comprises a polymeric sheet. 
     
     
         10 . The apparatus of  claim 9 , wherein the polishing material has:
 a plurality of discrete elements formed in the polishing surface and extending upward from the polishing surface; and   a plurality of grooves extending from the polishing surface toward the backside surface.   
     
     
         11 . The apparatus of  claim 10 , wherein the grooves define a repeating pattern in the polishing surface. 
     
     
         12 . A method of polishing a substrate, comprising:
 advancing a polishing material across a surface of a platen, wherein the polishing material has a polishing surface and an opposing backside surface, wherein the backside surface has a pattern of identifying features formed thereon;   sensing the movement of the pattern of identifying features past a detector assembly; and   controlling a position of the polishing material relative to the platen based on data received from the sensed movement of the pattern of identifying features.   
     
     
         13 . The method of  claim 12 , further comprising:
 halting the polishing material traveling across the surface of the platen when the detector assembly senses identifying features that indicate the start of a first region of polishing material having a desired pattern of polishing features;   urging a substrate toward the polishing material on the platen;   rotating the platen;   removing material from a surface of the substrate; and   advancing the polishing material relative to the platen after removing material from the surface of the substrate.   
     
     
         14 . The method of  claim 13 , further comprising:
 halting the polishing material across the surface of the platen when the detector assembly senses identifying features that indicate the start of a second region of polishing material having the desired pattern of polishing features.   
     
     
         15 . The method of  claim 14 , wherein the polishing features are selected from at least one of a plurality of discrete elements formed in the polishing surface and extending upward from the polishing surface and a plurality of grooves extending from the polishing surface toward the backside surface.