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.

We claim:  
     
         1 . A processing container for electrochemically processing a microelectronic workpiece comprising: 
 a principal fluid flow chamber;    a plurality of concentric anodes disposed at different elevations in the principal fluid flow chamber so as to place the concentric anodes at different distances from a microelectronic workpiece under process.    
     
     
         2 . A processing container as claimed in  claim 1  wherein one or more of the plurality of concentric anodes is disposed in close proximity to the microelectronic workpiece under process.  
     
     
         3 . A processing container as claimed in  claim 1  wherein the plurality of concentric anodes are arranged at increasing distances from the microelectronic workpiece from an outermost one of the plurality of concentric anodes to an innermost one of the plurality of concentric anodes.  
     
     
         4 . A processing container as claimed in  claim 1  wherein one or more of the plurality of concentric anodes is a virtual anode.  
     
     
         5 . A processing container as claimed in  claim 4  wherein the virtual anode comprises: 
 an anode chamber housing having a processing fluid inlet and a processing fluid outlet, the processing fluid outlet being disposed in close proximity to the microelectronic workpiece under process;  
 at least one conductive anode element disposed in the anode chamber housing.  
 
     
     
         6 . A processing container as claimed in  claim 4  wherein the at least one conductive anode element is formed from an inert material.  
     
     
         7 . A processing container as claimed in  claim 3  wherein one or more of the plurality of concentric anodes is a virtual anode.  
     
     
         8 . A processing container as claimed in  claim 7  wherein the virtual anode comprises: 
 an anode chamber housing having a processing fluid inlet and a processing fluid outlet, the processing fluid outlet being disposed in close proximity to the microelectronic workpiece under process;  
 at least one conductive anode element disposed in the anode chamber housing.  
 
     
     
         9 . A processing container as claimed in  claim 8  wherein the at least one conductive anode element is formed from an inert material.  
     
     
         10 . A processing container as claimed in  claim 1  and further comprising a plurality of nozzles disposed to provide a flow of the electrochemical processing fluid to the principal fluid flow chamber, the plurality of nozzles being arranged and directed to provide vertical and radial fluid flow components that combine to generate a substantially uniform normal flow component radially across the at least one surface of the workpiece;  
     
     
         11 . A processing container as claimed in  claim 1  wherein the principal fluid flow chamber is defined at an upper portion thereof by an angled wall, the angled wall supporting one or more of the plurality of concentric anodes.  
     
     
         12 . A processing container as claimed in  claim 3  wherein the principal fluid flow chamber is defined at an upper portion thereof by an angled wall, the angled wall supporting one or more of the plurality of concentric anodes.  
     
     
         13 . A processing container as claimed in  claim 3  wherein the principal fluid flow chamber further comprises an inlet disposed at a lower portion thereof that is configured to provide a Venturi effect that facilitates recirculation of processing fluid flow in a lower portion of the principal fluid flow chamber.  
     
     
         14 . A reactor for electrochemically processing at least one surface of a microelectronic workpiece, the reactor comprising: 
 a reactor head including a workpiece support;    one or more electrical contacts disposed on the workpiece support and positioned thereon to make electrical contact with the microelectronic workpiece;    a processing container including 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 disposed at different elevations in the principal fluid flow chamber so as to place the concentric anodes at different distances from a microelectronic workpiece under process without an intermediate diffuser between the plurality of anodes and the microelectronic workpiece under process.    
     
     
         15 . A reactor as claimed in  claim 14  wherein the plurality of nozzles are arranged and directed to provide vertical and radial fluid flow components that combine to generate a substantially uniform normal flow component radially across the at least one surface of the workpiece;  
     
     
         16 . A reactor as claimed in  claim 14  wherein one or more of the plurality of anodes is in close proximity to the workpiece under process.  
     
     
         17 . A reactor as claimed in  claim 14  wherein one or more of the plurality of concentric anodes is a virtual anode.  
     
     
         18 . A reactor as claimed in  claim 17  wherein the virtual anode comprises: 
 an anode chamber housing having a processing fluid inlet and a processing fluid outlet, the processing fluid outlet being disposed in close proximity to the microelectronic workpiece under process;  
 at least one conductive anode element disposed in the anode chamber housing.  
 
     
     
         19 . A reactor as claimed in  claim 18  wherein the at least one conductive anode element is formed from an inert material.  
     
     
         20 . A reactor as claimed in  claim 14  wherein the processing container is defined at an upper portion thereof by an angled wall, at least one of the plurality of anodes being supported by the angled wall.  
     
     
         21 . A reactor as claimed in  claim 14  and further comprising a rotor connected to rotate the workpiece support and an associated microelectronic workpiece at least during processing of the microelectronic workpiece.  
     
     
         22 . A reactor as claimed in  claim 14  and further comprising a plurality of nozzles angularly disposed in one or more sidewalls of the principal fluid flow chamber at a level within the principal fluid flow chamber below a surface of a bath of processing fluid contained therein during immersion processing.  
     
     
         23 . A method for electroplating a material on a microelectronic workpiece comprising the steps of: 
 introducing at least one surface of the microelectronic workpiece into an electroplating bath;    providing a plurality of anodes in the electroplating bath, the plurality of anodes being spaced at different distances from the at least one surface of the microelectronic workpiece that is to be electroplated;    inducing an electrical current between each of the plurality of anodes and the at least one surface of the microelectronic workpiece.    
     
     
         24 . A method as claimed in  claim 23  wherein each of the plurality of anodes is provided with a fixed electrical current over a substantial portion of the electroplating process.  
     
     
         25 . A method as claimed in  claim 23  and further comprising the step of providing a substantially uniform normal flow of electroplating solution to the at least one surface of the microelectronic workpiece.  
     
     
         26 . A method as claimed in  claim 23  and further comprising the step of providing a substantially uniform normal flow of electroplating solution to the at least one surface of the microelectronic workpiece without an intermediate diffuser disposed between the plurality of anodes and the at least one surface of the microelectronic workpiece.