Multi-Platen Multi-Head Polishing Architecture

Abstract

A polishing apparatus includes a plurality of stations supported on a platform, the plurality of stations including at least two polishing stations and a transfer station, each polishing station including a platen to support a polishing pad, a plurality of carrier heads suspended from and movable along a track such that each polishing station is selectively positionable at the stations, and a controller configured to control motion of the carrier heads along the track such that during polishing at each polishing station only a single carrier head is positioned in the polishing station.

1 - 17 . (canceled) 
     
     
         18 . A method of operating a polishing apparatus, comprising:
 transporting a first substrate from a transfer station past a first polishing station to a second polishing station without polishing the first substrate at the first polishing station;   transporting a second substrate from the transfer station to the first polishing station;   polishing the first substrate at the second polishing station and simultaneously polishing the second substrate at the first polishing station;   transporting the first substrate from the second polishing station past a third polishing station to a fourth polishing station without polishing the first substrate at the third polishing station;   transporting the second substrate from the first polishing station past the second polishing station to the third polishing station without polishing the second at the second polishing station; and   polishing the first substrate at the fourth polishing station and simultaneously polishing the second substrate at the third polishing station.   
     
     
         19 . The method of  claim 18 , further comprising transporting the first substrate from the fourth polishing station to the transfer station, and transporting the second substrate from the third polishing station past the fourth polishing station to the transfer station without polishing the second substrate at the fourth polishing station. 
     
     
         20 . The method of  claim 18 , wherein transporting the first substrate comprises holding the first substrate on a first carrier head and moving the first carrier head along a track, and wherein transporting the second substrate comprises holding the second substrate on a second carrier head and moving the second head along the track. 
     
     
         21 . A polishing apparatus comprising:
 N polishing stations where N is an even number equal to or greater than 4, each polishing station including a rotatable platen to support a polishing pad;   a substrate transport apparatus comprising a plurality of substrate transfer stations, a robot configured to transfer a substrate into a selectable one of the plurality of substrate transfer stations, and M carrier heads where M is an even number equal to or greater than N, each carrier head configured to receive a substrate from a substrate transfer station and to move from the substrate transfer station to a polishing station; and   a controller configured to cause the substrate transport apparatus to load a first substrate at a first transfer station into a first carrier head and load a second substrate at a second transfer station into a second carrier head, move the first substrate from the first transfer station to a first polishing station without polishing the first substrate at another station, move the second substrate to a second polishing station without polishing the second substrate at another station, simultaneously polish the first substrate at the first polishing station and the second substrate at the second polishing station in a first polishing step, move the first substrate from the first polishing station to a third polishing station without polishing the first substrate at another station and move the second substrate from the second polishing station to a fourth polishing station without polishing the second substrate at another station, simultaneously polish the first substrate at the third polishing station and the second substrate at the fourth polishing station in a second polishing step, and unload the first substrate and the second substrate from two of the plurality of carrier heads at the plurality of substrate transfer stations.   
     
     
         22 . The polishing apparatus of  claim 21 , wherein M equals N. 
     
     
         23 . The polishing apparatus of  claim 22 , wherein N is 4. 
     
     
         24 . The polishing apparatus of  claim 21 , wherein the N polishing stations are positioned at substantially equal angular intervals along a circular path. 
     
     
         25 . The polishing apparatus of  claim 24 , wherein the plurality of carrier heads are held by a support and are configured to move along the circular path. 
     
     
         26 . The polishing apparatus of  claim 25 , wherein the support comprises a track and the carrier heads are suspended from and movable along a track such that each carrier head station is selectively positionable at the polishing stations. 
     
     
         27 . The polishing apparatus of  claim 25 , wherein the support comprises a rotatable carousel and the carrier heads are suspended from the carousel such that rotation of the carousel moves the carrier heads along the circular path to position each carrier head at a polishing station. 
     
     
         28 . The polishing apparatus of  claim 27 , wherein the controller is configured to cause the transport apparatus to move the second substrate from the transfer stations through the first polishing station of the N polishing stations to the second polishing station of the N polishing stations without polishing the second substrate at the first polishing station and to move the first substrate from the transfer stations to the first polishing station. 
     
     
         29 . The polishing apparatus of  claim 28 , wherein the controller is configured to cause the transport apparatus to move the second substrate from the second polishing station through the third polishing station of the N polishing stations to the fourth polishing station of the N polishing stations without polishing the second substrate at the third polishing station and to move the first substrate from the first polishing station through the second polishing station to the third polishing station without polishing the first substrate at the second polishing station. 
     
     
         30 . The polishing apparatus of  claim 21 , wherein the controller is configured operate in one of a plurality of modes, and in a first mode of the plurality of modes the controller causes the transport apparatus to move the first substrate to a first half of the N polishing stations and cause the first substrate to be polished at the first half of the N polishing stations and to move the second substrate to a different second half of the N polishing stations and cause the second substrate to be polished the different second half of the N polishing stations, and in a second mode of the plurality of modes the controller causes the transport apparatus to move each substrate sequentially to each of the N polishing stations and cause the substrate to be polished at each of the N polishing stations.