Apparatus and methods to control the uniformity of electroplated workpiece

Abstract

An electroplating system for plating at least one metal on at least one substrate. At least one plating tank contains a plating solution including the at least one metal to be plated on the at least one substrate. At least one anode is arranged in the at least one plating tank. The at least one anode is at least partially immersed within the plating solution during plating of the at least one metal. At least one cathode includes at least one workpiece portion in contact with the at least one substrate and at least one thief portion arranged in the vicinity of at least one portion of the at least one substrate for controlling plating of the at least one metal on the at least one portion of the at least one substrate. At least one power supply is connected to the at least one cathode. At least one controller separately controls a flow of power to the at least one workpiece portion of the cathode and the at least one thief portion of the cathode.

We claim:  
     
         1 . An electroplating system for plating at least one metal on at least one substrate, said electroplating system comprising: 
 at least one plating tank containing a plating solution including said at least one metal to be plated on said at least one substrate;    at least one anode arranged in said at least one plating tank, said at least one anode being at least partially immersed within said plating solution during plating of said at least one metal;    at least one cathode including at least one workpiece portion in contact with said at least one substrate and at least one thief portion arranged in the vicinity of at least one portion of said at least one substrate for controlling plating of said at least one metal on said at least one portion of said at least one substrate;    at least one power supply connected to said at least one cathode; and    at least one controller for separately controlling a flow of power to said at least one workpiece portion of said cathode and said at least one thief portion of said cathode.    
     
     
         2 . The electroplating system according to  claim 1 , wherein said at least one controller includes a first timer for controlling a flow of power to said workpiece portion of said at least one cathode and said at least one substrate, and a second timer for controlling a flow of power to said at least one thief portion of said at least one cathode.  
     
     
         3 . The electroplating system according to  claim 1 , further comprising: 
 a power supply for each portion of said cathode.    
     
     
         4 . The electroplating system according to  claim 1 , wherein said at least one controller includes at least one timer for controlling a flow of power to each of said portions of said at least one cathode.  
     
     
         5 . The electroplating system according to  claim 2 , further comprising: 
 a third timer for controlling a flow of power to said second timer.    
     
     
         6 . The electroplating system according to  claim 5 , wherein said third timer delays the flow of power to said at least one thief portion of said at least one cathode to a point in time after power has been supplied to said at least one workpiece portion of said at least one cathode and said at least one substrate.  
     
     
         7 . A control system for controlling uniformity of electroplating of at least one metal on at least one substrate in an electroplating system including at least one plating tank containing a plating solution including said at least one metal to be plated on said at least one substrate, at least one anode arranged in said at least one plating tank, said at least one anode being at least partially immersed within said plating solution during plating of said at least one metal, at least one cathode including at least one workpiece portion in contact with said at least one substrate and at least one thief portion arranged in the vicinity of at least one portion of said at least one substrate for controlling plating of said at least one metal on said at least one portion of said at least one substrate, at least one power supply connected to said at least one cathode, said control system comprising: 
 at least one controller for separately controlling a flow of power to said at least one workpiece portion of said at least one cathode and said at least one thief portion of said at least one cathode.    
     
     
         8 . The control system according to  claim 7 , wherein said at least one controller includes a first timer for controlling a flow of power to said workpiece portion of said at least one cathode and said at least one substrate, and a second timer for controlling a flow of power to said at least one thief portion of said at least one cathode.  
     
     
         9 . The control system according to  claim 7 , wherein said electroplating system further includes a power supply for each portion of said cathode.  
     
     
         10 . The control system according to  claim 7 , wherein said at least one controller includes at least one timer for controlling a flow of power to each of said portions of said at least one cathode.  
     
     
         11 . The control system according to  claim 8 , further comprising: 
 a third timer for controlling a flow of power to said second timer.    
     
     
         12 . The control system according to  claim 11 , wherein said third timer delays the flow of power to said at least one thief portion of said at least one cathode to a point in time after power has been supplied to said at least one workpiece portion of said at least one cathode and said at least one substrate.  
     
     
         13 . A method of electroplating at least one metal on at least one substrate in an electroplating system including at least one plating tank containing a plating solution including said at least one metal to be plated on said at least one substrate, at least one anode arranged in said at least one plating tank, said at least one anode being at least partially immersed within said plating solution during plating of said at least one metal, at least one cathode including at least one workpiece portion in contact with said at least one substrate and at least one thief portion arranged in the vicinity of at least one portion of said at least one substrate for controlling plating of said at least one metal on said at least one portion of said at least one substrate, at least one power supply connected to said at least one cathode, said method comprising the steps of: 
 controlling a flow of power to said at least one workpiece portion of said at least one cathode; and    controlling a flow of power to said at least one thief portion of said at least one cathode separately from said flow of power to said at least one workpiece portion of said at least one cathode.    
     
     
         14 . The method according to  claim 13 , wherein the flow of power to said at least one thief portion of said at least one cathode is delayed to a point in time after power has been supplied to said at least one workpiece portion of said at least one cathode.  
     
     
         15 . The method according to  claim 13 , wherein controlling a flow of power to said at least one workpiece portion of said at least one cathode and said at least one thief portion of said at least one cathode includes controlling at least one parameter selected from the group consisting of current density and a time period that the current is applied.  
     
     
         16 . The method according to  claim 15 , further comprising the steps of: 
 supplying current to said at least one workpiece portion of said at least one cathode at a first current density for a first period of time; and    supplying current to said at least one thief portion of said at least one cathode at a second current density for a second period of time;    wherein said first current density, said second current density, said first period of time, and said second period of time are selected to result in a desired plating uniformity.    
     
     
         17 . A method of electroplating at least one metal on at least one substrate in an electroplating system, said method comprising the steps of: 
 providing an electroplating system including: 
 at least one plating tank containing a plating solution including said at least one metal to be plated on said at least one substrate;  
 at least one anode arranged in said at least one plating tank, said at least one anode being at least partially immersed within said plating solution during plating of said at least one metal;  
 at least one cathode including at least one workpiece portion in contact with said at least one substrate and at least one thief portion arranged in the vicinity of at least one portion of said at least one substrate for controlling plating of said at least one metal on said at least one portion of said at least one substrate;  
 at least one power supply connected to said at least one cathode; and  
 at least one controller for separately controlling a flow of power to said at least one workpiece portion of said cathode and said at least one thief portion of said cathode;  
   utilizing said at least one controller to control a flow of power to said at least one workpiece portion of said at least one cathode; and    utilizing said at least one controller to control a flow of power to said at least one thief portion of said at least one cathode separately from said flow of power to said at least one workpiece portion of said at least one cathode.    
     
     
         18 . The method according to  claim 17 , wherein said at least one controller includes a first timer for controlling a flow of power to said workpiece portion of said at least one cathode and said at least one substrate, and a second timer for controlling a flow of power to said at least one thief portion of said at least one cathode.  
     
     
         19 . The method according to  claim 17 , wherein said at least one controller further includes a third timer for controlling flow of power to said second timer, and said method further comprises the step of: 
 utilizing said third timer to control the controlling of the flow of power to said at least one thief portion of said at least one cathode.    
     
     
         20 . The method according to  claim 17 , wherein the flow of power to said at least one thief portion of said at least one cathode is delayed to a point in time after power has been supplied to said at least one workpiece portion of said at least one cathode.  
     
     
         21 . The method according to  claim 17 , wherein controlling a flow of power to said at least one workpiece portion of said at least one cathode and said at least one thief portion of said at least one cathode includes controlling at least one parameter selected from the group consisting of current density and a time period that the current is applied.  
     
     
         22 . A method of electroplating at least one metal on at least one substrate in an electroplating system including at least one plating tank containing a plating solution including said at least one metal to be plated on said at least one substrate, at least one anode arranged in said at least one plating tank, said at least one anode being at least partially immersed within said plating solution during plating of said at least one metal, at least one cathode including at least one workpiece portion in contact with said at least one substrate and at least one thief portion arranged in the vicinity of at least one portion of said at least one substrate for controlling plating of said at least one metal on said at least one portion of said at least one substrate, at least one power supply connected to said at least one cathode, said method comprising the step of: 
 decoupling a uniformity of said at least one metal deposited on said at least one substrate and a thickness of said at least one metal deposited on said at least one substrate.    
     
     
         23 . The method according to  claim 22 , wherein said decoupling is accomplished by providing said electroplating system with at least one controller for separately controlling a flow of power to said at least one workpiece portion of said at least one cathode and said at least one thief portion of said at least one cathode, and said method further comprises the steps of: 
 utilizing said at least one controller to control a flow of power to said at least one workpiece portion of said at least one cathode; and    utilizing said at least one controller to control a flow of power to said at least one thief portion of said at least one cathode.    
     
     
         24 . The method according to  claim 23 , wherein said at least one controller includes a first timer for controlling flow of power to said at least one workpiece portion of said at least one cathode, and a second timer for controlling flow of power to said at least one thief portion of said at least one cathode.  
     
     
         25 . The method according to  claim 24 , wherein said at least one controller further includes a third timer for controlling flow of power to said second timer, and said method further comprises the step of: 
 utilizing said third timer to control the controlling of the flow of power to said at least one thief portion of said at least one cathode.    
     
     
         26 . The method according to  claim 25 , wherein said third timer delays the flow of power to said at least one thief portion of said at least one cathode to a point in time after power has been supplied to said at least one workpiece portion of said at least one cathode.  
     
     
         27 . The method according to  claim 23 , wherein controlling a flow of power to said at least one workpiece portion of said at least one cathode and said at least one thief portion of said at least one cathode includes controlling at least one parameter selected from the group consisting of current density and a time period that the current is applied.