System for electrochemically processing a workpiece

Abstract

A reactor for electrochemically processing at least one surface of a microelectronic workpiece is set forth. The reactor comprises a reactor head including a workpiece support that has one or more electrical contacts positioned to make electrical contact with the microelectronic workpiece. The reactor also includes a processing container having a plurality of nozzles angularly disposed in a sidewall of a principal fluid flow chamber at a level within the principal fluid flow chamber below a surface of a bath of processing fluid normally contained therein during electrochemical processing. A plurality of anodes are disposed at different elevations in the principal fluid flow chamber so as to place them at difference distances from a microelectronic workpiece under process without an intermediate diffuser between the plurality of anodes and the microelectronic workpiece under process. One or more of the plurality of anodes may be in close proximity to the workpiece under process. Still further, one or more of the plurality of anodes may be a virtual anode. The present invention also related to multi-level anode configurations within a principal fluid flow chamber and methods of using the same.

1 - 22 . (canceled)  
     
     
         23 . An apparatus for electrochemical processing of microelectronic workpieces, comprising: 
 a head assembly having a workpiece holder including a contact assembly with a plurality of electrical contacts configured to engage a perimeter portion of a workpiece;    a processing chamber having a weir at a first elevation configured to define a surface level of electrochemical processing solution under the workpiece holder;    a first electrode in the processing chamber, a second electrode in the processing chamber concentric with the first electrode, and a dielectric separator between the first and second electrodes, wherein the dielectric separator is at a second elevation below the first elevation; and    an overflow collector external to the processing chamber to receive processing solution overflowing the weir.    
     
     
         24 . The apparatus of  claim 23  wherein the first electrode comprises a first annular conductive member and the second electrode comprises a second annular conductive member.  
     
     
         25 . The apparatus of  claim 24  wherein the first annular conductive member comprises a first conductive ring and the second annular conductive member comprises a second conductive ring.  
     
     
         26 . The apparatus of  claim 23 , further comprising a field shield between the workpiece holder and at least one of the electrodes configured to shield at least a portion of the workpiece from at least a portion of one of the electrodes.  
     
     
         27 . The apparatus of  claim 26  wherein the field shield comprises an annulus aligned with a peripheral portion of the workpiece holder.  
     
     
         28 . The apparatus of  claim 26  wherein the field shield comprises a flange extending transversely with respect to the central axis.  
     
     
         29 . The apparatus of  claim 26  wherein the field shield comprises a horizontal flange extending radially inward over a portion of the outer electrode.  
     
     
         30 . The apparatus of  claim 23  wherein the processing chamber further comprises a plurality of electrode chamber housings below the weir, the electrode chamber housings including a first electrode chamber housing containing the first electrode and a second electrode chamber housing containing the second electrode, wherein the second electrode chamber housing is concentric with the first electrode chamber housing.  
     
     
         31 . The apparatus of  claim 30  wherein the first electrode chamber housing is separated from the second electrode chamber housing by an annular wall.  
     
     
         32 . The apparatus of  claim 31  wherein the first electrode comprises a first annular conductive member and the second electrode comprises a second annular conductive member.  
     
     
         33 . The apparatus of  claim 32  wherein the first annular conductive member comprises a first conductive ring and the second annular conductive member comprises a second conductive ring.  
     
     
         34 . The apparatus of  claim 30  further comprising a first lateral dielectric member above the first electrode and a second dielectric member above the second electrode.  
     
     
         35 . The apparatus of  claim 23 , further comprising a controller operatively coupled to the electrodes, wherein the controller is programmed to apply a first current to the first conductive member and a second current different than the first current to the second conductive member.  
     
     
         36 . An apparatus for electrochemical processing of microelectronic workpieces, comprising: 
 a workpiece holder having a support member with an opening configured to receive a workpiece and a plurality of flexible conductive contacts projecting into the opening, the contacts having conductive contact portions arranged to contact a perimeter portion of the workpiece;    a processing chamber including a weir at a first elevation, a plurality of electrode compartments at one or more elevations below the first elevation, and a flow distributor configured to deliver processing solution to at least one electrode compartment;    a first electrode in the first electrode compartment and a second electrode in the second electrode compartment surrounding the first electrode; and    an overflow collector external to the processing chamber to receive processing solution overflowing the weir.    
     
     
         37 . The apparatus of  claim 36  wherein the first electrode comprises a first annular conductive member and the second electrode comprises a second annular conductive member.  
     
     
         38 . The apparatus of  claim 37  wherein the first annular conductive member comprises a first conductive ring and the second annular conductive member comprises a second conductive ring.  
     
     
         39 . The apparatus of  claim 36 , further comprising a field shield between the workpiece holder and at least one of the electrodes configured to shield at least a portion of the workpiece from at least a portion of one of the electrodes.  
     
     
         40 . The apparatus of  claim 39  wherein the field shield comprises an annulus aligned with a peripheral portion of the workpiece holder.  
     
     
         41 . The apparatus of  claim 39  wherein the field shield comprises a flange extending transversely with respect to the central axis.  
     
     
         42 . The apparatus of  claim 39  wherein the field shield comprises a horizontal flange extending radially inward over a portion of the outer electrode.  
     
     
         43 . The apparatus of  claim 36  wherein the first electrode compartment comprises a first electrode chamber housing containing the first electrode and the second electrode compartment comprises a second electrode chamber housing containing the second electrode, wherein the second electrode chamber housing is concentric with the first electrode chamber housing.  
     
     
         44 . The apparatus of  claim 43  wherein the first electrode chamber housing is separated from the second electrode chamber housing by an annular wall.  
     
     
         45 . The apparatus of  claim 44  wherein the first electrode comprises a first annular conductive member and the second electrode comprises a second annular conductive member.  
     
     
         46 . The apparatus of  claim 45  wherein the first annular conductive member comprises a first conductive ring and the second annular conductive member comprises a second conductive ring.  
     
     
         47 . The apparatus of  claim 43  further comprising a first lateral dielectric member above the first electrode and a second dielectric member above the second electrode.  
     
     
         48 . The apparatus of  claim 36 , further comprising a controller operatively coupled to the electrodes, wherein the controller is programmed to apply a first current to the first conductive member and a second current different than the first current to the second conductive member.  
     
     
         49 . An apparatus for electrochemical processing of microelectronic workpieces, comprising: 
 a head assembly having a workpiece holder including a contact assembly with a plurality of electrical contacts configured to engage a perimeter portion of. a workpiece;    a processing chamber having a inner vessel, an annular dielectric divider in the inner vessel at one elevation, and a weir at another elevation above the elevation of the dielectric divider;    a plurality of electrodes in the inner vessel, the plurality of electrodes including a first electrode being an innermost electrode relative to a central axis of the processing chamber and a second electrode surrounding the first electrode; and    an external overflow collector around the processing chamber.    
     
     
         50 . An tool for electrochemical processing of microelectronic workpieces, comprising: 
 a cabinet having a plurality of processing stations;    a robotic transfer mechanism for transferring microelectronic workpieces relative to the processing stations;    an electrochemical processing apparatus at a processing station, the electrochemical processing apparatus having a head assembly, a processing chamber having a weir at a first elevation and an annular dielectric divider at a second elevation below the first elevation, a plurality of independently operable electrodes in the processing chamber including a first electrode on one side of the divider and a second electrode on another side of the divider, and an overflow collector external to the processing chamber, the head assembly having a workpiece holder configured to carry a workpiece and a contact assembly including a plurality of contacts arranged to contact a perimeter portion of the workpiece, and the overflow collector being configured to receive processing solution overflowing the weir.    
     
     
         51 . A method for processing a microelectronic workpiece in a processing station having an exterior cup, a processing chamber in the exterior cup, a first electrode in the processing chamber, and a second electrode in the processing chamber arranged concentrically with the first electrode, comprising: 
 directing a flow of processing solution through the processing chamber;    providing an electrical current to the workpiece via a plurality of electrical contacts engaging a perimeter portion of the workpiece;    applying a first electrical bias to the first electrode;    applying a second electrical bias to the second electrode; and    flowing the processing solution over a weir of the processing chamber and into an external overflow collector.    
     
     
         52 . The method of  claim 51  wherein the first electrical bias applied to the first electrode is different than the second electrical bias applied to the second electrode.  
     
     
         53 . An apparatus for electrochemically processing microelectronic workpieces, comprising: 
 a workpiece holder including contact means for electrically biasing a workpiece and for holding the workpiece at a processing region;    means for directing a uniform electrolyte flow upwardly toward the workpiece holder to crest at the processing region, the directing means being in a processing chamber;    means for biasing the electrolyte flow differentially relative to a radial position within the processing chamber, wherein the biasing means includes first and second electrically conductive electrodes in the processing chamber; and    overflow means for receiving the electrolyte flow downstream from the processing region, wherein the processing chamber is a separate vessel relative to the overflow means.    
     
     
         54 . The apparatus of  claim 53  wherein the overflow means comprises an exterior cup containing the processing chamber.