Apparatuses, systems and methods that allow for selective removal of a specific metal from a multi-metal plating solution

Patent metadata

Field	Value
Publication number	US-9428841-B2
Application number	US-201414283667-A
Country	US
Kind code	B2
Filing date	May 21, 2014
Priority date	May 21, 2014
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

Disclosed is an apparatus wherein an electric circuit with at least a power source, two electrodes and a plating solution is established. The plating solution comprises a solvent and, dissolved in the solvent, at least a first metal and a second metal. The power source supplies a current to the electric circuit during a plating process. The amount of electric current is above that required to achieve the overpotential for plating the first metal, but below that required to achieve the overpotential for plating the second metal such that only the first metal plates. This apparatus can be implemented, for example, in conjunction with a plating apparatus or an analysis and dosing apparatus of an electrodeposition system. In the case of an analysis and dosing apparatus, additional components further allow for the addition of that specific metal back into the plating solution. Also disclosed herein are associated methods.

First claim

What is claimed is:

1. An electrodeposition system comprising:
a plating apparatus; and,
a plating solution analysis and dosing apparatus comprising:
a container comprising a membrane separating a first compartment and a second compartment, said first compartment containing a plating solution that circulates between said plating apparatus and said plating solution analysis and dosing apparatus and said second compartment containing an additional solution,
said plating solution comprising a solvent and, dissolved in said solvent, a first metal and a second metal different from said first metal,
said additional solution comprising said solvent and being devoid of said first metal and said second metal,

a first electrode in said plating solution;
a second electrode in said additional solution;
a power source having a negative terminal and a positive terminal;
a polarity-switching unit electrically connected to said negative terminal, said positive terminal, said first electrode, and said second electrode; and
a controller operatively connected to said power source and said polarity-switching unit and controlling said power source and said polarity-switching unit so as to selectively cause any one of the following within said plating solution analysis and dosing apparatus: performance of a first metal plating process; performance of a first metal de-plating process; and establishment and maintenance of an equilibrium potential,

said controller causing said power source to turn off in order to establish and maintain said equilibrium potential,
said controller causing said polarity-switching unit to electrically connect said first electrode to said negative terminal and said second electrode to said positive terminal so as to form a first electric circuit and further causing said power source to turn on and supply a first operating current to said first electric circuit in order to perform said first metal plating process, said first operating current causing said first metal to plate on said first electrode such that a first concentration of said first metal in said plating solution is decreased and such that a second concentration of said second metal in said plating solution remains constant, and
said controller causing said polarity-switching unit to electrically connect said first electrode to said positive terminal and said second electrode to said negative terminal so as to form a second electric circuit and further causing said power source to turn on and supply a second operating current to said second electric circuit in order to perform said first metal de-plating process, said second operating current causing said first metal to de-plate from said first electrode such that said first concentration of said first metal in said plating solution is increased.

2. The system of claim 1 ,
said first operating current being a predetermined current amount between a first current amount required to achieve a first activation overpotential for plating said first metal on said first electrode and a second current amount required to achieve a second activation overpotential for plating said second metal on said first electrode, and
said second operating current being sufficient to achieve a third activation overpotential for de-plating said first metal from said first electrode.

3. The system of claim 2 , further comprising:
a reference electrode in said plating solution and electrically connected to said negative terminal; and
a potentiometer electrically connected to said reference electrode and said second electrode,
said controller operably connected to said potentiometer and said power source,
said potentiometer measuring a potential difference between said reference electrode and said second electrode during said performance of said first metal plating process, and
said controller selectively adjusting said first operating current so that said potential difference remains between said first activation overpotential and said second activation overpotential.

4. The system of claim 1 , further comprising at least one agitator agitating said plating solution and said additional solution during both said performance of said first metal plating process and said performance of said first metal de-plating process.

5. The system of claim 1 , said first electrode comprising a conductive sheet comprising any one of a solid sheet and a mesh sheet.

6. The system of claim 1 , said first metal being silver and said second metal being tin.

7. The system of claim 1 , further comprising a plating solution analyzer in communication with said controller and determining a composition of said plating solution in said first compartment, said controller selectively causing said one of said performance of said first metal plating process, said performance of said first metal de-plating process and said maintenance of said equilibrium potential, based on said composition.

8. The system of claim 1 , further comprising a dosing device adding at least one additive to said plating solution in said first compartment during said performance of said first metal de-plating process.

9. An electrodeposition system comprising:
a plating apparatus; and,
a plating solution analysis and dosing apparatus comprising:
a container comprising a membrane separating a first compartment and a second compartment, said first compartment containing a plating solution that circulates between said plating apparatus and said plating solution analysis and dosing apparatus and said second compartment containing an additional solution,
said plating solution comprising a solvent and, dissolved in said solvent, a first metal and a second metal different from said first metal,
said additional solution comprising said solvent and being devoid of said first metal and said second metal,

a first electrode in said plating solution;
a second electrode in said additional solution;
a power source having a negative terminal and a positive terminal;
a polarity-switching unit electrically connected to said negative terminal, said positive terminal, said first electrode, and said second electrode; and
a controller operatively connected to said power source and said polarity-switching unit and controlling said power source and said polarity-switching unit so as to selectively cause any one of the following within said plating solution analysis and dosing apparatus: performance of a first metal plating process; performance of a first metal de-plating process; and establishment and maintenance of an equilibrium potential.

10. The system of claim 9 , further comprising at least one agitator agitating said plating solution and said additional solution during both said performance of said first metal plating process and said performance of said first metal de-plating process.

11. The system of claim 9 , further comprising a plating solution analyzer in communication with said controller and determining a composition of said plating solution in said first compartment, said controller selectively causing said one of said performance of said first metal plating process, said performance of said first metal de-plating process and said maintenance of said equilibrium potential, based on said composition.

Assignees

• IBM
• Globalfoundries Inc

Inventors

• Arvin Charles L
• Dutka Stephen G
• Palmatier Phillip W
• Pennacchia John R
• Torres Freddie

Classifications

• C25D21/12 Primary

  Process control or regulation (controlling or regulating in general G05) · CPC title

• C25D21/16

  Regeneration of process solutions · CPC title

• C25D21/18

  of electrolytes (C25D21/22 takes precedence) · CPC title

• C25D21/14 Primary

  Controlled addition of electrolyte components · CPC title

• C25D21/10

  Agitating of electrolytes; Moving of racks · CPC title