Current collimation for thin seed and direct plating

Abstract

A method and apparatus for plating a conductive material onto a substrate is provided. The apparatus includes a fluid processing cell having a fluid basin configured to contain an electrolyte solution and having an opening configured to receive a substrate for processing, an anode assembly positioned in the fluid basin, and a collimator positioned in the fluid basin between the anode assembly and the opening.

1 . A fluid processing cell, comprising: 
 a fluid basin configured to contain an electrolyte solution and having an opening configured to receive a substrate for processing;    an anode assembly positioned in the fluid basin; and    a collimator positioned in the fluid basin between the anode and the opening.    
   
   
       2 . The fluid processing cell of  claim 1 , wherein the collimator comprises a plurality of electrically insulative fluid conduits.  
   
   
       3 . The fluid processing cell of  claim 2 , wherein the fluid conduits are positioned such that a longitudinal axis of each of the conduits is parallel to each of the other longitudinal axes of the conduits.  
   
   
       4 . The fluid processing cell of  claim 1 , wherein the collimator comprises a plurality of fluid conduits positioned such that a longitudinal axis of each of the conduits is generally perpendicular to an upper surface of the anode assembly.  
   
   
       5 . The fluid processing cell of  claim 3 , wherein an upper terminating end of the conduits is positioned between about 0.5 mm and about 15 mm from a substrate processing position.  
   
   
       6 . The fluid processing cell of  claim 5 , wherein a lower terminating end of the conduits is positioned between about 0.5 mm and about 15 mm from at least one of the anode assembly and a membrane positioned across the fluid basin between the anode assembly and the opening.  
   
   
       7 . The fluid processing cell of  claim 6 , wherein a horizontal cross section of an individual conduit is at least one of a circle, square, triangle, hexagon, pentagon, or other polygon.  
   
   
       8 . The fluid processing cell of  claim 2 , wherein the fluid conduits are circular and have an interior diameter of between about 1 mm and about 10 mm.  
   
   
       9 . The fluid processing cell of  claim 1 , wherein the anode assembly comprises a plurality of individually powered polygon shaped anode members that cooperatively form a substantially planar upper anode surface.  
   
   
       10 . An electrochemical plating cell, comprising: 
 a cell body configured to contain a plating solution therein and having an opening configured to receive a substrate for plating;    an anode assembly positioned in the cell body such that the anode assembly is in electrical communication with the plating solution; and    an electric field collimator positioned in the cell body between the anode assembly and the opening, the collimator comprising a plurality of electrically insulative fluid conduits having substantially parallel longitudinal axes.    
   
   
       11 . The electrochemical plating cell of  claim 10 , wherein each of the plurality of electrically insulative fluid conduits has an inner diameter of less than about 20 mm.  
   
   
       12 . The electrochemical plating cell of  claim 10 , wherein each of the plurality of electrically insulative fluid conduits has an inner diameter of between about 1 mm and about 10 mm.  
   
   
       13 . The electrochemical plating cell of  claim 10 , wherein an upper surface of the electric field collimator is positioned between about 0.5 mm and about 20 mm from a substrate processing position.  
   
   
       14 . The electrochemical plating cell of  claim 10 , wherein a lower surface of the electric field collimator is positioned between about 2 mm and about 20 mm from at least one of an upper surface of the anode assembly and a membrane positioned across the cell body between the anode assembly and the opening.  
   
   
       15 . The electrochemical plating cell of  claim 10 , wherein the electric field collimator comprises more than about 500 electrically insulative fluid conduits.  
   
   
       16 . The electrochemical plating cell of  claim 15 , wherein the diameter of the collimator is between about 275 mm and about 325 mm.  
   
   
       17 . The electrochemical plating cell of  claim 16 , wherein the opening is sized to receive a substrate having a diameter greater than about 275 mm.  
   
   
       18 . The electrochemical plating cell of  claim 10 , wherein the electric field collimator occupies between about 50% and about 99% of vertical space between the anode assembly and the substrate.  
   
   
       19 . The electrochemical plating cell of  claim 10 , wherein the electric field collimator comprises a disk shaped insulative material having a plurality of bores formed therethrough which define the fluid conduits.  
   
   
       20 . The electrochemical plating system of  claim 10 , wherein the anode assembly comprises a plurality of individually powered square shaped anode members, each of the square shaped anode members having an electrically insulating spacer positioned around the perimeter thereof.  
   
   
       21 . A method for plating a conductive material onto a substrate, comprising: 
 generating an electric field between an anode positioned in a plating cell and a substrate being plated in the plating cell;    collimating the electric field in a substantially linear direction between the anode and the substrate; and    plating the conductive material onto the substrate.    
   
   
       22 . The method of  claim 21 , wherein collimating further comprises: 
 receiving the electric field into a first opening of an electrically insulating collimator;    transmitting the electric field to a second opening of the collimator via a substantially linear fluid conduit connecting the first and second openings; and    transmitting the electric field toward the substrate from the second opening.    
   
   
       23 . The method of  claim 22 , wherein the second opening is positioned between about 0.5 mm and about 20 mm from the substrate.  
   
   
       24 . The method of  claim 22 , wherein the first opening is positioned between about 1 mm and about 20 mm from the anode.  
   
   
       25 . The method of  claim 22 , wherein the substantially linear fluid conduit connecting the first and second openings has a longitudinal axis that is generally perpendicular to an upper surface of the anode.  
   
   
       26 . The method of  claim 22 , wherein the electrically insulating collimator occupies between about 50% and about 99% of vertical space between the anode and the substrate.  
   
   
       27 . The method of  claim 21 , generating the electric field comprises individually powering a plurality of polygon shaped anode members.  
   
   
       28 . The method of  claim 27 , further comprising controlling plating uniformity by controlling power application to the individual anode members.