Electrochemical deposition apparatus and methods for controlling the chemistry therein
An electrochemical deposition system is described. The electrochemical deposition system includes one or more electrochemical deposition modules arranged on a common platform for depositing one or more metals on a substrate, and a chemical management system coupled to the one or more electrochemical deposition modules. The chemical management system is configured to supply at least one of the one or more electrochemical deposition modules with one or more metal constituents for depositing the one or more metals. The chemical management system can include at least one metal enrichment cell and at least one metal-concentrate generator cell.
1. A metal-concentrate generator apparatus for replenishing a plating system, comprising:
a metal-concentrate generator cell that defines an anolyte region, a catholyte region, and a metal-ion capture region disposed between said anolyte region and said catholyte region, said metal concentrate generator cell including a soluble anode disposed in said anolyte region, an inert cathode disposed in said catholyte region, a first ion exchange membrane disposed between said anolyte region and said metal-ion capture region, and a second ion exchange membrane disposed between said catholyte region and said metal-ion capture region;
a power source electrically coupled to said soluble anode and said inert cathode that generates metal-ions from said soluble anode when electrical current flows between said soluble anode and said inert cathode;
an anolyte reservoir and a first pump that circulates said anolyte through said anolyte region of said metal-concentrate generator cell;
a metal-concentrate dispensing system coupled to an output of said first pump via a first valve, and arranged to supply doses of said metal-concentrate to one or more electrochemical deposition modules without receiving a recirculation of said metal-concentrate from the plating system;
a metal-ion capture reservoir and a second pump that circulates a metal-ion capture solution through said metal-ion capture region;
a catholyte reservoir and a third pump that circulates said catholyte through said catholyte region; and
a recycle line coupling said metal-ion capture reservoir to said anolyte reservoir, and a fourth pump for transferring at least part of said metal-ion capture solution from said metal-ion capture reservoir to said anolyte reservoir.
2. The apparatus of claim 1 , further comprising:
a monitoring system coupled to said metal-ion capture reservoir and arranged to measure a metal-ion concentration in said metal-ion capture solution.
3. The apparatus of claim 1 , further comprising:
a monitoring system coupled to the anolyte reservoir and arranged to measure metal-ion concentration in an anolyte solution.
4. The apparatus of claim 1 , further comprising:
a chemical control system coupled to said fourth pump, and programmed to transfer at least part of said metal-ion capture solution from said metal-ion capture reservoir to said metal-concentrate reservoir when a metal-ion concentration of said metal-ion capture solution is at or exceeds a threshold value.
5. The apparatus of claim 4 , wherein said metal concentration includes Sn and said threshold value is about 30 g/l.
6. The apparatus of claim 1 , wherein said dispensing system comprises a metal-concentrate storage reservoir, and a dosing system that controllably meters introduction of metal-concentrate from said metal-concentrate storage reservoir to said one or more electrochemical deposition modules.
7. The apparatus of claim 1 , wherein said dispensing system comprises a dosing system that controllably meters introduction of metal-concentrate from said anolyte reservoir to said one or more electrochemical deposition modules by opening and closing said first valve.
8. The apparatus of claim 1 , wherein said first ion exchange membrane is selected of a material that reduces transport of said metal-ions from said anode region to said metal-ion capture region.
9. The apparatus of claim 1 , wherein said first ion exchange membrane and said second ion exchange membrane include an anionic membrane.