Systems and methods for removing contaminants in electroplating systems

Abstract

Electroplating systems according to the present technology may include a two-bath electroplating chamber including a separator configured to provide fluid separation between a first bath configured to maintain a catholyte during operation and a second bath configured to maintain an anolyte during operation. The system may include a catholyte tank fluidly coupled with the first bath of the two-bath electroplating chamber. The system may also include a contaminant retrieval system configured to remove contaminant ions from the catholyte.

What is claimed is: 
     
         1 . An electroplating system comprising:
 a two-bath electroplating chamber including a separator configured to provide fluid separation between a first bath configured to maintain a catholyte during operation and a second bath configured to maintain an anolyte during operation;   a catholyte tank fluidly coupled with the first bath of the two-bath electroplating chamber; and   a contaminant retrieval system configured to remove contaminant ions from the catholyte.   
     
     
         2 . The electroplating system of  claim 1 , wherein the contaminant retrieval system comprises a vessel positioned fluidly inline between the first bath and the catholyte tank. 
     
     
         3 . The electroplating system of  claim 2 , wherein the vessel comprises an anode and a cathode electrically coupled with a power supply. 
     
     
         4 . The electroplating system of  claim 3 , wherein the anode comprises a first material that is consumable or inert to the catholyte. 
     
     
         5 . The electroplating system of  claim 4 , wherein the catholyte comprises a solution including tin, wherein the contaminant ions comprise copper, and wherein the first material comprises tin. 
     
     
         6 . The electroplating system of  claim 4 , wherein the first material comprises a material inert to the catholyte and more noble than copper. 
     
     
         7 . The electroplating system of  claim 3 , wherein the power supply is configured to operate at a voltage below a plating potential for tin within the electroplating system. 
     
     
         8 . The electroplating system of  claim 7 , wherein the power supply is configured to operate at a voltage above a plating potential for copper within the electroplating system. 
     
     
         9 . The electroplating system of  claim 2 , wherein the vessel comprises a packed bed of tin-containing particles. 
     
     
         10 . The electroplating system of  claim 1 , wherein the contaminant retrieval system comprises a packed bed of tin-containing particles positioned in the catholyte tank. 
     
     
         11 . A method of removing copper contaminants from a tin-containing catholyte within an electroplating system, the method comprising:
 flowing the catholyte from an electroplating chamber to a catholyte tank,   passing the catholyte across a tin-containing material, and   reducing the copper contaminants from the catholyte.   
     
     
         12 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 11 , wherein the tin-containing material comprises an anode of an anode-cathode pair of electrically coupled electrodes. 
     
     
         13 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 12 , wherein the anode and cathode are driven at a voltage below a tin plating potential and above a copper plating potential. 
     
     
         14 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 12 , wherein the cathode comprises tin or a material more noble than copper. 
     
     
         15 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 12 , wherein the tin-containing material is maintained in a vessel positioned between and fluidly coupled with the electroplating chamber and the catholyte tank. 
     
     
         16 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 11 , wherein the tin-containing material comprises a packed column of the tin-containing material. 
     
     
         17 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 11 , wherein the tin-containing material is disposed within the catholyte tank. 
     
     
         18 . An electroplating system comprising:
 an electroplating chamber;   an electrolyte tank fluidly coupled with the electroplating chamber and configured to maintain an electrolyte;   a tin-containing electrolyte including copper ions; and   a contaminant retrieval system configured to remove the copper ions from the electrolyte, wherein the contaminant retrieval system comprises a single component system of a tin-containing material, or a dual component system of a tin-containing material or a material more noble than copper on the electromotive force series.   
     
     
         19 . The electroplating system of  claim 18 , wherein the contaminant retrieval system comprises a vessel positioned between the electroplating chamber and the electrolyte tank, and wherein the vessel houses the single component system or the dual component system. 
     
     
         20 . The electroplating system of  claim 18 , wherein the contaminant retrieval system is configured in operation to maintain an increase in copper ion concentration within the electrolyte below about 1 ppm per five thousand wafers processed.