Electroplating apparatus with segmented anode array

Abstract

An electroplating apparatus includes a reactor vessel having a segmented anode array positioned therein for effecting electroplating of an associated workpiece such as a semiconductor wafer. The anode array includes a plurality of ring-like anode segments which are preferably positioned in concentric, coplanar relationship with each other. The anode segments can be independently operated to create varying electrical potentials with the associated workpiece to promote uniform deposition of electroplated metal on the surface of the workpiece.

What is claimed is:  
     
         1 . An electroplating apparatus for electroplating a workpiece, comprising: 
 an electroplating reactor including a reactor vessel for holding electroplating solution; and    a segmented anode array positioned in said reactor vessel for immersion in the plating solution,    said anode array comprising a plurality of anode segments having differing dimensions, said array being operable to facilitate uniform deposition of electroplated metal on said workpiece.    
     
     
         2 . An electroplating apparatus in accordance with  claim 1 , wherein 
 said reactor vessel defines an axis with the workpiece being positionable in generally transverse relationship to said axis;    said anode array being configured such that at least one of said anode segments having a relatively greater dimension is positioned further from said axis than another one of said anode segments having a relatively lesser dimension.    
     
     
         3 . An electroplating apparatus in accordance with  claim 1 , wherein 
 said plurality of anode segments are generally coplanar.    
     
     
         4 . An electroplating apparatus in accordance with  claim 1 , wherein 
 said plurality of anode segments are coaxial.    
     
     
         5 . An electroplating apparatus in accordance with  claim 4 , wherein 
 each of said anode segments is circular, with said anode segments being concentric with each other.    
     
     
         6 . An electroplating apparatus in accordance with  claim 1 , wherein 
 said segmented anode array includes a mounting base upon which said anode segments are mounted, said mounting base defining at least one flow passage for directing flow of the electroplating solution between adjacent ones of said anode segments.    
     
     
         7 . An electroplating apparatus in accordance with  claim 1 , including 
 dielectric means positioned between at least two adjacent ones of said anode segments for facilitating uniform deposition of electroplated metal on the workpiece.    
     
     
         8 . An electroplating apparatus for electroplating a workpiece, comprising: 
 an electroplating reactor including a cup-shaped reactor vessel for holding electroplating solution, said reactor vessel defining an axis, with the workpiece being positionable in generally transverse relationship to said axis,    a segmented anode array positioned generally at the lower extent of said reactor vessel in generally perpendicular relationship to said axis, said anode array comprising a plurality of circular anode segments arranged in concentric relationship to each other about said axis.    
     
     
         9 . An electroplating apparatus in accordance with  claim 8 , wherein 
 said plurality of anode segments are generally coplanar.    
     
     
         10 . An electroplating apparatus in accordance with  claim 8 , wherein 
 each of said anode segments is of a generally toroidal configuration.    
     
     
         11 . An electroplating apparatus in accordance with  claim 8 , wherein 
 said segmented anode array includes a mounting base upon which said anode segments are mounted, said mounting base defining at least one flow passage for directing flow of the electroplating solution therethrough.    
     
     
         12 . An electroplating apparatus in accordance with  claim 11 , wherein 
 a central-most one of said anode segments defines an opening aligned with said axis, said flow passage defined by said mounting base being aligned with said opening.    
     
     
         13 . An electroplating apparatus in accordance with  claim 11 , wherein 
 said flow passage is positioned generally between two adjacent ones of said anode segments for directing flow of the electroplating solution therebetween.    
     
     
         14 . An electroplating apparatus in accordance with  claim 13 , including 
 a plurality of said flow passages arranged in a pattern of concentric circles to direct flow from electroplating solution between adjacent ones of said anode segments.    
     
     
         15 . An electroplating apparatus in accordance with  claim 11 , wherein 
 said mounting base includes a plurality of depending, flow-modulating projections defining flow channels therebetween.    
     
     
         16 . An electroplating apparatus in accordance with  claim 8 , including 
 control means operatively connected to said segmented anode array for independently operating said plurality of anode segments.