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 . A method of removing copper contaminants from a tin-containing catholyte within an electroplating system, the method comprising:
 flowing the tin-containing catholyte from an electroplating chamber to a catholyte tank;   passing the tin-containing catholyte across a tin-containing material; and   reducing a copper contaminant concentration in the tin-containing catholyte.   
     
     
         2 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 1 , wherein the tin-containing material comprises an anode of an anode-cathode pair of electrically coupled electrodes. 
     
     
         3 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 2 , wherein the anode-cathode pair are driven at a voltage below a tin plating potential and above a copper plating potential. 
     
     
         4 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 2 , wherein a cathode of the anode-cathode pair comprises tin or a material more noble than copper. 
     
     
         5 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 2 , wherein the tin-containing material is maintained in a vessel positioned between and fluidly coupled with the electroplating chamber and the catholyte tank. 
     
     
         6 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 1 , wherein the tin-containing material comprises a packed column of the tin-containing material. 
     
     
         7 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 1 , wherein the tin-containing material is disposed within the catholyte tank. 
     
     
         8 . A method of removing copper contaminants from a tin-containing catholyte within an electroplating system, the method comprising:
 flowing the tin-containing catholyte from an electroplating chamber to a catholyte tank, wherein the catholyte tank comprises an anode-cathode pair of electrically coupled electrodes;   applying a voltage to the anode-cathode pair of electrically coupled electrodes; and   reducing a copper contaminant concentration from the tin-containing catholyte.   
     
     
         9 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 8 , wherein the voltage is below a plating potential for tin. 
     
     
         10 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 8 , wherein the voltage is less than 2.3 V. 
     
     
         11 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 8 , wherein the voltage is greater than 1.5 V. 
     
     
         12 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 8 , further comprising:
 subsequent to a first period of time, increasing the voltage.   
     
     
         13 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 8 , wherein a cathode of the anode-cathode pair comprises tin or a material more noble than copper. 
     
     
         14 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 8 , wherein the copper contaminant concentration is maintained at less than or about 10 ppm. 
     
     
         15 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 14 , wherein the copper contaminant concentration is maintained at less than or about 10 ppm after processing more than or about 1,000 substrates. 
     
     
         16 . A method of removing copper contaminants from a tin-containing catholyte within an electroplating system, the method comprising:
 flowing the tin-containing catholyte from an electroplating chamber to a catholyte tank, wherein the catholyte tank comprises an anode-cathode pair of electrically coupled electrodes;   applying a first voltage to the anode-cathode pair of electrically coupled electrodes for a first period of time;   subsequent to the first period of time, increasing the first voltage to a second voltage;   applying the second voltage to the anode-cathode pair of electrically coupled electrodes for a second period of time; and   reducing a copper contaminant concentration from the tin-containing catholyte.   
     
     
         17 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 16 , wherein the first voltage and the second voltage are greater than or about 1.5 V. 
     
     
         18 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 16 , wherein the first voltage and the second voltage are less than or about 2.3 V. 
     
     
         19 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 16 , wherein the copper contaminant concentration is maintained at less than or about 10 ppm. 
     
     
         20 . The method of removing copper contaminants from a tin-containing catholyte within an electroplating system of  claim 19 , wherein the copper contaminant concentration is maintained at less than or about 10 ppm after processing more than or about 1,000 substrates.