Means to eliminate bubble entrapment during electrochemical processing of workpiece surface

Abstract

Methods and systems are provided to eliminate bubble entrapment during electrochemical processing of a substrate, wherein a rigid plate with fluid openings allow process solution to flow between the front surface of the substrate and an electrode. The plate includes a protruding region. In operation, the protruding region causes a raised solution surface to touch the front surface of the wafer prior to complete immersion of the substrate in the solution. In other embodiments, the raised surface of the solution can be provided by applying pressure to a flexible pad or other workpiece surface influencing device (WSID).

1 . A method of immersing a surface of a wafer in a solution for processing the surface, comprising: 
 flowing the solution through openings of a rigid plate having a protruding region to form a raised solution surface over the protruding region;    contacting a selected portion of the wafer surface with the raised solution surface; and    immersing the wafer surface fully into the solution.    
   
   
       2 . The method of  claim 1 , further comprising rotating the wafer before contacting.  
   
   
       3 . The method of  claim 1 , wherein the selected portion of the surface is a center of the surface of the wafer.  
   
   
       4 . The method of  claim 1 , further comprising placing the rigid plate into the solution.  
   
   
       5 . The method of  claim 1 , further comprising processing the surface of the wafer.  
   
   
       6 . A system for eliminating bubble entrapment under a surface of a wafer when the surface is immersed into a process solution to process the surface of the wafer, comprising: 
 a rigid plate, having a protruded region and fluid openings, wherein the plate is configured such that as the solution flows through the rigid plate, a raised solution surface forms over the protruded region; and    a moving mechanism configured to move the wafer, wherein as the wafer is moved towards the solution, a selected portion of the surface of the wafer contacts the raised solution surface before immersing the surface fully into the solution.    
   
   
       7 . The system of  claim 6 , wherein the protruded region forms a portion of a top surface of the rigid plate.  
   
   
       8 . The system of  claim 6 , wherein the protruded region forms a top surface of the rigid plate.  
   
   
       9 . The system of  claim 6 , further including an electrode placed in the process solution.  
   
   
       10 . The system of  claim 9 , further including a power supply connected to the electrode and the surface of the wafer to apply a potential difference between the surface of the wafer and the electrode to process the surface.  
   
   
       11 . The system of  claim 9 , wherein the rigid plate is placed between the electrode and the surface of the wafer.  
   
   
       12 . The system of  claim 6 , wherein the rigid plate has a rectangular shape.  
   
   
       13 . The system of  claim 6 , wherein the selected portion of the surface is a center of the surface of the wafer.  
   
   
       14 . A method of processing a conductive surface of a wafer using a process solution, comprising: 
 flowing the solution through openings of a plate having a protruding region to form a raised solution surface over the protruding region;    contacting a selected portion of the conductive surface with the raised solution surface;    immersing the conductive surface fully into the solution; and    processing the conductive surface.    
   
   
       15 . The method of  claim 14 , further comprising applying a potential difference between the conductive surface and an electrode.  
   
   
       16 . The method of  claim 15 , wherein processing is electropolishing.  
   
   
       17 . The method of  claim 15 , wherein processing is electrodeposition.  
   
   
       18 . The method of  claim 14 , further comprising rotating the conductive surface before the step of contacting.  
   
   
       19 . The method of  claim 14 , wherein the selected portion of the conductive surface is a center of the conductive surface of the wafer.  
   
   
       20 . The method of  claim 14 , wherein the plate is rigid.  
   
   
       21 . A system for electroprocessing a conductive surface of a wafer using a process solution, comprising: 
 an electrode configured to be placed in the process solution;    a rigid plate, having a protruded region and fluid openings, configured to be immersed in the solution and positioned between the electrode and the conductive surface, wherein the rigid plate is configured such that as the solution flows through the rigid plate, a raised solution surface forms over the protruded region; and    a moving mechanism configured to move the wafer, wherein as the wafer is moved towards the solution, a selected portion of the conductive surface contacts the raised solution surface before immersing the surface fully into the solution.    
   
   
       22 . The system of  claim 21 , wherein the rigid plate is placed between the electrode and the conductive surface of the wafer.  
   
   
       23 . The system of  claim 21 , wherein the rigid plate has a rectangular shape.  
   
   
       24 . The system of  claim 21 , wherein the selected portion of the conductive surface is s center of the conductive surface of the wafer.  
   
   
       25 . The system of  claim 21 , wherein the protruded region forms a portion of a top surface of the rigid plate.  
   
   
       26 . The system of  claim 21 , wherein the protruded region forms a top surface of the rigid plate.  
   
   
       27 . The system of  claim 21 , further including a power supply connected to the electrode and the surface of the wafer to apply a potential difference between the conductive surface of the wafer and the electrode to process the conductive surface of the wafer.