Apparatus and method for plating solution analysis

Abstract

A method and apparatus for analyzing plating solutions. The apparatus generally includes a plating cell, a reference electrolyte input, one or more external additive pumps, and a process controller. In one embodiment, the plating cell includes a cavity therein having a larger volumetric portion adjacent a smaller volumetric portion adapted to hold one or more solutions therein. The plating cell also includes a base disposed adjacent the bottom of the plating cell and adapted to receive and mix one or more test solutions as part of the plating solution analysis. In one configuration, the base includes electrical ports adapted to connect stimulation signals to a working electrode, counter electrode, and reference electrode disposed within the cell. The base also includes a thermal sensor in thermal contact with test solutions contained within the vessel.

1 . A system for analyzing one or more plating solutions used in a substrate plating process, comprising; a plating cell disposed on a frame having a base thereon, wherein the base is disposed adjacent a conical bottom cavity portion of the plating cell and adapted to couple a plurality of solutions to the plating cell; a motor coupled to the plating cell and adapted to rotate a working electrode therein; and a plurality of pumps disposed on the frame and in fluidic communication with the base, the pumps are adapted to pump the one or more solutions to the base, wherein the one or more solutions are combined within the base and plating cell to define a test plating solution to be analyzed.  
   
   
       2 . The system of  claim 1 , wherein the plating cell comprises an upper cavity portion having a larger volume than the conical cavity portion.  
   
   
       3 . The system of  claim 1 , wherein the base comprises a plurality of fluid ports thereon adapted to couple one or more fluids from the fluid pumps to the plating cell.  
   
   
       4 . The system of  claim 3 , wherein the fluid ports are coupled to a fluid junction adapted to combine one or more fluids pumped into the fluid ports into the test plating solution.  
   
   
       5 . The system of  claim 3 , wherein the fluid ports are coupled to a fluid junction adapted to direct a stream of the one or more solutions toward the working electrode to dislodge air bubbles therefrom during a fill process.  
   
   
       6 . The system of  claim 5 , further comprising a heat exchanger disposed on the plating cell and adapted to control a temperature of the one or more plating solutions.  
   
   
       7 . The system of  claim 6 , wherein the heat exchanger comprises a thermoelectric heat module in thermal contact with the plating cell and adapted to control a temperature of the one or more solutions.  
   
   
       8 . The system of  claim 6 , further comprising a process controller coupled to at least one of the plating cell, the heat exchanger, and the pumps.  
   
   
       9 . The system of  claim 8 , wherein the process controller is adapted to control a potentiostat to drive one or more stimulus signals between the working electrode and a counter electrode disposed in the base.  
   
   
       10 . The system of  claim 8 , wherein the process controller is adapted to receive a reference signal from a reference electrode disposed in the base.  
   
   
       11 . The system of  claim 8 , wherein the process controller is adapted to control at least one operation of the plating cell, the heat exchanger, thermoelectric modules, and the pumps.  
   
   
       12 . The system of  claim 1 , wherein the base comprises a fluid exit port having an oblong cross-section adapted to provide a desired surface tension to prevent leakage of the one or more plating solutions from the plating cell prior to discharge, and provide a rapid discharge when the one or more plating solutions are discharged from the plating cell.  
   
   
       13 . A method of analyzing solutions used in a plating process, comprising: receiving at least one fluid and at least one solution into a fluid hub; mixing the at least one fluid and at least one solution in the fluid hub to form a test solution; delivering the test solution to a vessel; isolating the at least one fluid and at least one solution from each other; providing a liquid plug of the at least one solution between the fluid hub and the test solution contained in the vessel; providing an electrolyte slug in contact with a reference electrode; wherein the electrolyte slug is in contact with the test solution; and testing the test solution.  
   
   
       14 . The method of  claim 13 , wherein receiving comprises providing a plurality of fluid delivery paths to couple external fluids to the fluid hub, the fluid delivery paths are configured to fluidically inhibit the intrusion of the at least one solution into the at least one fluid.  
   
   
       15 . The method of  claim 13 , wherein isolating comprises providing an air plug between the at least one fluid and the test solution.  
   
   
       16 . The method of  claim 13 , wherein providing the electrolyte slug comprises fluidically inhibiting a flow of the electrolyte between the electrolyte and the test solution.  
   
   
       17 . The method of  claim 16 , wherein providing an electrolyte slug comprises providing a passage for an electrolyte to contact the test solution, wherein the passage is configured to prevent density driven fluid exchange between the electrolyte and the test solution.  
   
   
       18 . The method of  claim 13 , further comprising combining a plurality of fluids to form a premixed version of the at least one fluid.  
   
   
       19 . The method of  claim 18 , wherein combining comprises mixing the plurality of fluids in the fluid hub.  
   
   
       20 . The method of  claim 18 , wherein combining comprises mixing the plurality of fluids in the vessel.