Methods and apparatus for using a bevel polishing head with an efficient tape routing arrangement

Abstract

Apparatus and methods are provided to polish an edge of a substrate. The invention includes a polishing head, adapted to contact an edge of a substrate, wherein the polishing head includes one pair of front guide rollers and two pairs of back clamping rollers. Numerous other aspects are provided.

1 . An apparatus for polishing an edge of a substrate, the apparatus comprising:
 a polishing head, adapted to contact an edge of a substrate, wherein the polishing head includes at least one front roller adapted to guide a polishing tape and at least one pair of back rollers adapted to maintain an alignment of the polishing tape.   
   
   
       2 . The apparatus of  claim 1  wherein the front and back rollers are adapted to rotate. 
   
   
       3 . The apparatus of  claim 1  wherein the polishing head includes a pad. 
   
   
       4 . The apparatus of  claim 3  wherein the polishing head is adapted to guide the polishing tape over the pad. 
   
   
       5 . The apparatus of  claim 4  wherein the pad is adapted to press the polishing tape to contact the edge of the substrate. 
   
   
       6 . The apparatus of  claim 4  wherein the polishing tape is routed between a first pair of back rollers, around a first front roller and a second front roller, and then between a second pair of back rollers. 
   
   
       7 . The apparatus of  claim 6  wherein a length of polishing tape between the first and second front rollers is adapted to contact the edge of the substrate. 
   
   
       8 . The apparatus of  claim 1  wherein the polishing head is adapted to rock about the edge of the substrate. 
   
   
       9 . The apparatus of  claim 1  wherein the back rollers are self-locking. 
   
   
       10 . The apparatus of  claim 6  wherein the polishing tape is constrained from slipping off the pad by the back rollers. 
   
   
       11 . A system for polishing an edge of a substrate, the system comprising:
 a substrate support adapted to rotate a substrate;   a polishing head adapted to contact an edge of a substrate, wherein the polishing head includes one pair of front rollers and two pairs of back rollers;   a controller adapted to operate the polishing of the edge of the substrate.   
   
   
       12 . The system of  claim 11  wherein the polishing head includes a polishing tape. 
   
   
       13 . The system of  claim 12  wherein the polishing head is adapted to contact the edge of the substrate with the polishing tape. 
   
   
       14 . The system of  claim 12  wherein the polishing tape is routed between the first pair of back rollers, around the first and second front rollers, and then between the second pair of back rollers. 
   
   
       15 . The system of  claim 14  wherein the length of polishing tape between the first and second front rollers contacts the edge of the substrate. 
   
   
       16 . The system of  claim 12  wherein the controller is adapted to incrementally advance the polishing tape to the polishing head. 
   
   
       17 . The system of  claim 14  wherein the polishing tape is constrained in the lateral direction by the back rollers. 
   
   
       18 . The system of  claim 11  wherein the front and back rollers are adapted to rotate. 
   
   
       19 . The system of  claim 11  wherein the polishing head is adapted to rock about the edge of the substrate. 
   
   
       20 . A method for polishing an edge of a substrate comprising:
 rotating a substrate;   contacting an edge of the substrate with a polishing head, wherein the polishing head includes one pair of front rollers and two pairs of back rollers;   routing a polishing tape between the first pair of back rollers, around the first and second front rollers, and then between the second pair of back rollers, such that the length of polishing tape between the first and second front rollers contacts and polishes the edge of the substrate.   
   
   
       21 . The method of  claim 20  further comprising:
 advancing the polishing tape in increments.   
   
   
       22 . The method of  claim 20  further comprising:
 advancing the polishing tape continuously.   
   
   
       23 . The method of  claim 20  further comprising:
 constraining the polishing tape in the lateral direction between each pair of back rollers.   
   
   
       24 . The method of  claim 20  further comprising:
 pressing the polishing tape against the edge of the substrate via a pad.   
   
   
       25 . The method of  claim 20  further comprising:
 rocking the polishing head about the edge of the substrate.