Electrochemical plating cell having a membrane stack

Abstract

Embodiments of the invention generally provide an electrochemical plating cell having cell body defining a fluid containing region, an anode positioned in the fluid containing region, and a membrane stack positioned across the fluid containing region at a position above the anode and below a substrate receiving opening formed into the cell body. The membrane stack includes an ionic membrane, a first membrane stack positioned on an upper surface of the ionic membrane, and a second membrane stack position on a lower surface of the ionic membrane.

1 . An electrochemical plating cell, comprising: 
 a fluid basin having a fluid inlet and a fluid outlet;    an ionic membrane sealably positioned across the fluid basin to separate the fluid basin into a catholyte volume and an anolyte volume;    an anode positioned in the anolyte volume;    a first membrane stack positioned on a first side of the ionic membrane; and    a second membrane stack positioned on a second side of the ionic membrane.    
     
     
         2 . The plating cell of  claim 1 , wherein the first membrane stack comprises: 
 a first membrane positioned adjacent the ionic membrane, the first membrane having a thickness of between about 50 um and about 150 um; and    a second membrane positioned adjacent the first membrane and between the first membrane and a substrate being plated, the second membrane having a thickness of between about 30 um and about 175 um.    
     
     
         3 . The plating cell of  claim 2 , wherein first membrane has a pore diameter of between about 2 um and about 20 um.  
     
     
         4 . The plating cell of  claim 2 , wherein the second membrane has a pore diameter of between about 0.1 um and about 15 um.  
     
     
         5 . The plating cell of  claim 4 , wherein the first membrane has a pore diameter of between about 2 um and about 20 um.  
     
     
         6 . The plating cell of  claim 1 , wherein the second membrane stack comprises a third membrane positioned adjacent the second side of the ionic membrane and a fourth membrane positioned between the third membrane and the anode.  
     
     
         7 . The plating cell of  claim 6 , wherein the third membrane has a pore diameter of between about 2 um and about 20 um.  
     
     
         8 . The plating cell of  claim 6 , wherein the fourth membrane has a pore diameter of between about 0.1 um and about 15 um.  
     
     
         9 . The plating cell of  claim 8 , wherein the third membrane has a pore diameter of between about 2 um and about 20 um.  
     
     
         10 . The plating cell of  claim 6 , further comprising an anolyte drain in fluid communication with a fluid volume positioned between the second side of the ionic membrane and the third membrane.  
     
     
         11 . The plating cell of  claim 6 , further comprising a catholyte drain in fluid communication with a fluid volume positioned between the first side of the ionic membrane and the first membrane.  
     
     
         12 . The plating cell of  claim 1 , further comprising a third membrane stack positioned on an upper surface of the anode, the third membrane stack comprising a fifth membrane positioned adjacent the upper surface and a sixth membrane positioned above the fifth membrane.  
     
     
         13 . The plating cell of  claim 12 , wherein the fifth membrane has a pore diameter of between about 2 um and about 20 um.  
     
     
         14 . The plating cell of  claim 13 , wherein the sixth membrane has a pore diameter of between about 0.1 um and about 15 um.  
     
     
         15 . The plating cell of  claim 13 , wherein the sixth membrane has a pore diameter of between about 0.1 um and about 15 um.  
     
     
         16 . An electrochemical plating cell, comprising: 
 a cell body defining a fluid containing region;    an anode positioned in the fluid containing region; and    a membrane stack positioned across the fluid containing region at a position above the anode and below a substrate receiving opening formed into the cell body, the membrane stack comprising: 
 an ionic membrane;  
 a first membrane stack positioned on an upper surface of the ionic membrane; and  
 a second membrane stack position on a lower surface of the ionic membrane.  
   
     
     
         17 . The plating cell of  claim 16 , where the first membrane stack comprises: 
 a first membrane positioned next to the upper surface, the first membrane having a pore diameter of between about 2 um and about 20 um; and    a second membrane positioned adjacent the first membrane and between the first membrane and a substrate being plated, the second membrane having a pore diameter of between about 0.1 um and about 15 um.    
     
     
         18 . The plating cell of  claim 16 , wherein the second membrane stack comprises a third membrane positioned adjacent the lower surface of the ionic membrane and having a pore diameter of between about 2 um and about 20 um, and a fourth membrane positioned between the third membrane and the anode and having a pore diameter of between about 0.1 um and about 15 um.  
     
     
         19 . The plating cell of  claim 16 , further comprising an anolyte drain in fluid communication with a fluid volume positioned between the lower side of the ionic membrane and the third membrane.  
     
     
         20 . The plating cell of  claim 16 , further comprising a catholyte drain in fluid communication with a fluid volume positioned between the upper side of the ionic membrane and the first membrane.  
     
     
         21 . The plating cell of  claim 16 , further comprising a third membrane stack positioned on an upper surface of the anode, the third membrane stack comprising a fifth membrane positioned adjacent the upper surface and a sixth membrane positioned above the fifth membrane.  
     
     
         22 . The plating cell of  claim 21 , wherein the fifth membrane has a pore diameter of between about 2 um and about 20 um and the sixth membrane has a pore diameter of between about 0.1 um and about 15 um.  
     
     
         23 . An electrochemical plating cell, comprising: 
 a fluid basin having a fluid inlet and a fluid outlet configured to receive a substrate;    an anode position in the fluid basin;    a cationic membrane positioned across the fluid basin;    a first membrane positioned over the cationic membrane and having a pore diameter of between about 2 um and about 20 um;    a second membrane positioned over the first membrane and having a pore diameter of between about 0.1 um and about 15 um;    a third membrane positioned under the cationic membrane and having a pore diameter of between about 2 um and about 20 um;    a fourth membrane positioned under the third membrane and having a pore diameter of between about 0.1 um and about 15 um;    a first fluid outlet in fluid communication with a fluid volume between the first membrane and the cationic membrane; and    a second fluid outlet in fluid communication with a fluid volume between the ionic membrane and the third membrane.    
     
     
         24 . The plating cell of  claim 23 , wherein the ionic membrane is positioned at a tilt angle.  
     
     
         25 . The plating cell of  claim 23 , further comprising: 
 a fifth membrane positioned on an upper surface of the anode, the fifth membrane having a pore diameter of between about 2 um and about 20 um; and    a sixth membrane positioned over the fifth membrane and having a pore diameter of between about 0.1 um and about 15 um.    
     
     
         26 . The plating cell of  claim 25 , further comprising a fluid drain in communication with a fluid volume between the upper surface of the anode and the fifth membrane.