Insoluble Anode With a Plurality of Switchable Conductive Elements Used to Control Current Density in a Plating Bath

Abstract

This application relates to systems and methods for controlling current density in an electrochemical bath using an anode assembly that comprises a plurality of anodes arranged across a surface of the anode assembly. In one embodiment, each of the anodes may be coupled to a power supply through an intervening electrical switch. A switch controller enables the selection of which anodes should be turned on or off during processing. In this way, current density across the anode assembly can be controlled in a uniform manner by turning on and off select anodes. Turning off a portion of the anodes may lower current density in that region. Likewise, turning on the portion of anodes will increase the current density in that region.

What is claimed is: 
     
         1 . An anode assembly for use in an electrolytic processing system, comprising:
 an anode structure comprising a plurality of anodes;   a plurality of electrically controlled switches arranged to be disposed between a power source and said plurality of anodes, each of said electrically controlled switches being configured to couple electrical current from said power source to one or more of said plurality of anodes; and   a controller coupled to said plurality of electrically controlled switches, and programmed to set said plurality of electrically controlled switches to a pre-determined configuration of on and off-state for each of said plurality of anodes.   
     
     
         2 . The anode assembly of  claim 1 , wherein said pre-determined configuration includes a first set of said electrically controlled switches set to an off-state to disconnect current flow to a first set of said plurality of anodes, and a second set of said electrically controlled switches set to an on-state to connect current flow to a second set of said plurality of anodes. 
     
     
         3 . The anode assembly of  claim 1 , wherein said plurality of anodes are housed within a dielectric member or a conductive member. 
     
     
         4 . The anode assembly of  claim 3 , further comprising:
 an electrode disposed behind said dielectric member, and electrically coupled to two or more of said plurality of anodes, said electrode being electrically coupled to one of said plurality of electrically controlled switches.   
     
     
         5 . The anode assembly of  claim 3 , further comprising:
 a first electrode disposed behind said dielectric member, and electrically coupled to two or more of said plurality of anodes centrally located in said anode structure, said first electrode being electrically coupled to one of said plurality of electrically controlled switches; and   a second electrode disposed behind said dielectric member, and electrically coupled to two or more of said plurality of anodes peripherally located in said anode structure, said second electrode being electrically coupled to another of said plurality of electrically controlled switches.   
     
     
         6 . The anode assembly of  claim 1 , wherein a first electrically controlled switch is electrically coupled to a first array of said plurality of anodes, and a second electrically controlled switch is electrically coupled to a second array of said plurality of anodes. 
     
     
         7 . The anode assembly of  claim 1 , wherein said plurality of anodes comprise a plurality of insoluble anodes. 
     
     
         8 . The anode assembly of  claim 1 , wherein at least one of a number density or a size of said plurality of anodes are turned on or off across a first dimension of said anode structure. 
     
     
         9 . An electrochemical deposition system, comprising:
 a cathode;   an anode assembly disposed opposite said cathode;   a power source coupled to said anode assembly and said cathode, and configured to supply an electrical current between said anode assembly and said cathode through an electrochemical medium, wherein said anode assembly comprises:
 an anode structure comprising a plurality of anodes, and 
 a plurality of electrically controlled switches disposed between said power source and said plurality of anodes, each of said electrically controlled switches being configured to couple electrical current from said power source to said one or more of said plurality of anodes; and 
   a controller coupled to said plurality of electrically controlled switches, and programmed to set said plurality of electrically controlled switches to a pre-determined configuration of on and off-state for each of said plurality of anodes.   
     
     
         10 . The anode assembly of  claim 9 , wherein at least one of said plurality of anodes is positioned at a first axial distance from said cathode, and at least another of said plurality of anodes is positioned at a second axial distance from said cathode. 
     
     
         11 . The anode assembly of  claim 9 , wherein at least one of said plurality of anodes is substantially flush with the anode assembly, recessed into the anode assembly, or protruding from the anode assembly. 
     
     
         12 . A method for processing a substrate in an electrochemical deposition system, comprising:
 disposing an anode structure in an electrochemical deposition system opposite a substrate, and contacting said anode structure with an electrochemical medium contained between said anode structure and said substrate, said anode structure comprising a plurality of anodes;   providing a plurality of electrically controlled switches coupled between a power source and said plurality of anodes, each of said electrically controlled switches being configured to couple electrical current from said power source to one or more of said plurality of anodes;   determining a first configuration of an on and off-state for each of said plurality of anodes;   spatially controlling an anode current at said anode structure by setting said plurality of electrically controlled switches to said first configuration of said on and off-state of said plurality of anodes; and   electrochemically depositing a film on said substrate.   
     
     
         13 . The method of  claim 12 , further comprising:
 determining a second configuration of an on and off-state for each of said plurality of anodes; and   switching from said first configuration to said second configuration of said on and off-state for each of said plurality of anodes.   
     
     
         14 . The method of  claim 13 , wherein said switching is performed during said electrochemically depositing. 
     
     
         15 . The method of  claim 13 , wherein said switching is performed following electrochemically depositing said film on said substrate and electrochemically depositing another film on another substrate. 
     
     
         16 . The method of  claim 12 , wherein said determining said first configuration comprises identifying an on or off-state of a first set of at least one of said plurality of anodes with a first region on said substrate. 
     
     
         17 . The method of  claim 16 , wherein said first region includes one or more dies. 
     
     
         18 . The method of  claim 12 , wherein each of said plurality of anodes is coupled exclusively to a corresponding electrical switch. 
     
     
         19 . The method of  claim 12 , wherein said plurality of anodes comprise at least one group of anodes that are coupled to one electrical switch and a portion of anodes that are exclusively coupled to their own electrical switch. 
     
     
         20 . The method of  claim 12 , wherein each of said plurality of anodes comprise a diameter between 1 mm to 5 mm.