Electroplating processor with vacuum rotor

Abstract

A substrate processor uses pressurized gas to create a vortex for lifting and holding a wafer, and to create a vacuum to prevent the wafer from adhering to a contact ring seal after electroplating the wafer. A processor head has a rotor movable into and out of an electrolyte vessel. A backing plate on the rotor includes vortex outlets which create the vortex in the rotor. A vacuum channel adjacent to the perimeter of the rotor applies vacuum to the wafer edges to hold the wafer onto the backing plate. A solenoid or switch in the head has a first position to supply gas flow to the vortex outlets, and a second position to supply gas flow to an aspirator which creates the vacuum in the vacuum channel.

1 . A substrate processor, comprising:
 a bowl for containing an electrolyte;   a head having a rotor movable into and out of the bowl;   a plurality of vortex outlets in the rotor between a center of the rotor and a perimeter of the rotor;   a vacuum channel adjacent to the perimeter of the rotor;   a switch in the head having a first position wherein a flow of pressurized gas is supplied to the vortex outlets, and a second position wherein a flow of pressurized gas is supplied to an aspirator creating a vacuum in the vacuum channel.   
     
     
         2 . The substrate processor of  claim 1  with the switch comprising a solenoid. 
     
     
         3 . The substrate processor of  claim 1  further comprising an actuator in the head operable via gas flow when the switch is in the second position. 
     
     
         4 . The substrate processor of  claim 3  with the rotor including a backing plate and with the plurality of vortex outlets and the vacuum channel in the backing plate. 
     
     
         5 . The substrate processor of  claim 4  with the rotor further including a contact ring movable towards and away from the backing plate. 
     
     
         6 . The substrate processor of  claim 5  with the actuator linked to a vacuum pad connected to the aspirator, and with the vacuum pad spaced apart from the backing plate when the switch is in the first position, and with the vacuum pad moved into contact with a vacuum pad landing on the backing plate when the switch is in the second position. 
     
     
         7 . The substrate processor of  claim 6  with actuator spring biased to hold the vacuum pad spaced apart from the backing plate. 
     
     
         8 . The substrate processor of  claim 1  further comprising a wafer ejector in the vacuum channel. 
     
     
         9 . The substrate processor of  claim 8  with the wafer ejector comprising a spring. 
     
     
         10 . The substrate processor of  claim 9  with the spring comprising a non-metallic Bellville washer. 
     
     
         11 . The substrate processor of  claim 1  further comprising a vacuum sensor in the head for sensing a vacuum in the vacuum channel. 
     
     
         12 . A substrate processor, comprising:
 a vessel;   one or more electrodes in the vessel;   a head having a rotor including a backing plate having a plurality of vortex outlets, and a vacuum channel adjacent to the perimeter of the backing plate;   a contact ring on the head movable axially from a load/unload position spaced apart from the backing plate, to a process position adjacent to the backing plate, with the contact ring having a plurality of contact fingers and a seal for sealing the contact fingers from electrolyte in the vessel;   a head lifter for moving the head towards and away from the vessel;   a pressurized gas line leading into the head; and   a solenoid in the head switchable between a first position wherein a flow of pressurized gas is supplied from the pressurized gas line to the vortex outlets, and a second position wherein a flow of pressurized gas is supplied to an aspirator and an actuator to create a vacuum in the vacuum channel.   
     
     
         13 . The processor of  claim 12  with the actuator moving a vacuum pad to connect to, and separate from, a vacuum port in the backing plate connected to the vacuum channel. 
     
     
         14 . A method for processing a wafer, comprising
 moving the wafer into a head of a processor;   lifting the wafer into contact with the head using a gas vortex;   moving a contact ring on the head into contact with the wafer;   placing the wafer in an electrolyte and sealing the electrolyte from the contact ring via a seal;   passing electrical current through the electrolyte to form a layer of conductive material on the wafer;   applying vacuum to the perimeter of the wafer to hold the wafer onto the backing plate;   moving the contact ring away from the backing plate, with the wafer remaining on the backing plate; and   removing the wafer from the processor.   
     
     
         15 . The method of  claim 14  further including indexing the rotor to align a vacuum pad in the head with a vacuum pad landing on the backing plate.