Patent ID: 9227293
Filing Date: 2016-01-05
CPC Classification: B24B

Claim Text:
1. A polishing apparatus comprising: N polishing stations, where N is an even number equal to or greater than 4, each polishing station including a platen to support a polishing pad; an even number of carrier heads held by a support structure and movable to the N polishing stations in sequence, the N polishing stations including a first polishing station, a second polishing station, a third polishing station and a fourth polishing station; a transfer station; and a controller configured to cause two substrates to be loaded into two of the carrier heads in the transfer station, move the two of the carrier heads to a first pair of the N polishing stations, simultaneously polish the two substrates in a first polishing step at the first pair of the N polishing stations, move the two of the carrier heads to a second pair of the N polishing stations, simultaneously polish the two substrates in a second polishing step at the second pair of the N polishing stations, move the two of the carrier heads to the transfer station, and cause the two substrates to be unloaded from the two of the carrier heads; wherein the controller is configured to move the two of the carrier heads to the first pair of the N polishing stations by moving a first carrier head with a first substrate from the transfer station through the first polishing station of the N polishing stations to the second polishing station of the N polishing stations without polishing the first substrate at the first polishing station and moving a second carrier head with a second substrate from the transfer station to the first polishing station, and wherein the controller is configured to move the two of the carrier heads to the second pair of the N polishing stations by moving the first carrier head with the first 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 first substrate at the third polishing station and moving the second carrier head with the second substrate from the first polishing station through the second polishing station to the third polishing station without polishing the second substrate at the second polishing station.