Electrolytic Cell with Electrically Neutral and Conductive Sieve

Abstract

An electrochemical deposition fountain reactor for processing spinning semiconductor wafers can include a perforated ionic membrane near the wafer surface through which electrolyte flows. This allows high velocity electrolyte jets to impinge the wafer surface at low bulk flow rates, which reduces the boundary layer at the wafer surface and allows for better replenishment of ions at the wafer surface.

What is claimed is: 
     
         1 . An electrolytic cell comprising:
 an electrochemical reactor including a housing defining a chamber and an electrically neutral and conductive sieve mounted within the chamber and configured to direct jets of electrolyte toward a workpiece that is configured to rotate within the chamber.   
     
     
         2 . The electrolytic cell of  claim 1 , wherein the electrically neutral and conductive sieve is a perforated ionic membrane. 
     
     
         3 . The electrolytic cell of  claim 2 , wherein perforations of the perforated ionic membrane are of different size. 
     
     
         4 . The electrolytic cell of  claim 2 , wherein perforations of the perforated ionic membrane are of different shape. 
     
     
         5 . The electrolytic cell of  claim 1 , wherein the electrically neutral and conductive sieve is arranged parallel to and spaced away from the workpiece. 
     
     
         6 . The electrolytic cell of  claim 1 , wherein the electrically neutral and conductive sieve is disk shaped. 
     
     
         7 . The electrolytic cell of  claim 1  further comprising a support mounted within the chamber between the electrically neutral and conductive sieve and the workpiece and in direct areal contact with the electrically neutral and conductive sieve. 
     
     
         8 . The electrolytic cell of  claim 7 , wherein the support is a grate. 
     
     
         9 . An electrochemical deposition apparatus comprising:
 a disk-shaped electrically neutral and conductive sieve configured to be mounted within an electrochemical reactor in a spaced relationship from a rotating semiconductor wafer associated with the electrochemical reactor, and defining a plurality of perforations configured to direct jets of electrolyte toward the rotating semiconductor wafer that disrupt a boundary layer of electrolyte at a surface of the rotating semiconductor wafer.   
     
     
         10 . The apparatus of  claim 9 , wherein the disk-shaped electrically neutral and conductive sieve is a perforated ionic membrane. 
     
     
         11 . The apparatus of  claim 10 , wherein perforations of the perforated ionic membrane are of different size. 
     
     
         12 . The apparatus of  claim 10 , wherein perforations of the perforated ionic membrane are of different shape. 
     
     
         13 . The apparatus of  claim 9 , wherein the disk-shaped electrically neutral and conductive sieve is arranged parallel to and spaced away from the rotating semiconductor wafer. 
     
     
         14 . The apparatus of  claim 9  further comprising a support configured to be mounted within the electrochemical reactor between the disk-shaped electrically neutral and conductive sieve and the rotating semiconductor wafer and in direct areal contact with the disk-shaped electrically neutral and conductive sieve. 
     
     
         15 . The apparatus of  claim 14 , wherein the support is a grate.