System and methods for measuring chemical concentrations of a plating solution

• US 7,851,222 B2
• Filed: 07/26/2005
• Issued: 12/14/2010
• Est. Priority Date: 07/26/2005
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Ta, Kathryn P., Hoermann, Alexander F., Rabinovich, Yevgeniy
• Primary Examiner(s): Nagpaul; Jyoti
• Application Number:
  US11/189,368
• Publication Number:
  US 20070026529A1
• Time in Patent Office: 1,967 Days
• Field of Search: 436/53, 436/180, 204/195, 204/198, 204/240, 422 99-100
• US Class Current: 436/53
• CPC Class Codes: C25D 17/001 Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• CPC Class Codes: C25D 21/12 Process control or regulation controlling or regulating in general G05
• CPC Class Codes: Y10T 436/118339 with formation of a segmented stream
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

An electrochemical plating system, which includes one or more plating cell reservoirs for storing plating solution and a chemical analyzer in fluidic communication with the one or more plating cell reservoirs. The chemical analyzer is configured to measure chemical concentrations of the plating solution. The plating system further includes a plumbing system configured to facilitate the fluidic communication between the one or more plating cell reservoirs and the chemical analyzer and to substantially isolate the chemical analyzer from electrical noise generated by one or more plating cells of the one or more plating cell reservoirs.

Claims

1. An electrochemical plating system, comprising:

one or more plating cell reservoirs for storing plating solution;

a chemical analyzer in fluidic communication with the one or more plating cell reservoirs, wherein the chemical analyzer is configured to measure chemical concentrations of the plating solution;

a sampling reservoir coupled to the chemical analyzer, wherein the sampling reservoir is configured to hold a portion of the plating solution;

a plumbing system configured to facilitate the fluidic communication between the one or more plating cell reservoirs and the chemical analyzer and to substantially isolate the chemical analyzer from electrical noise generated by one or more plating cells of the one or more plating cell reservoirs, wherein the plumbing system comprises at least one valve that allows the portion of the plating solution to flow from the one or more plating cell reservoirs to the sampling reservoir, when the at least one valve is in an open position; and

a system controller, wherein the system controller comprises a microprocessor, and wherein the system controller is configured to receive inputs and use the inputs to control;

(i) circulating a portion of a plating solution through the chemical analyzer; and

(ii) switching the at least one valve to a closed position once the sampling reservoir is filled with the portion of the plating solution to substantially isolate the chemical analyzer from the electrical noise generated by the one or more plating cells.

2. The system of claim 1, wherein the plumbing system comprises a first flow path for delivering the portion of the plating solution from the one or more plating cell reservoirs to the sampling reservoir.

3. The system of claim 1, wherein the plumbing system comprises a second flow path for circulating the portion of the plating solution through the chemical analyzer.

4. The system of claim 1, wherein the plumbing system comprises a third flow path for returning the portion of the plating solution to the one or more plating cell reservoirs.

5. The system of claim 4, wherein the system controller further controls using the third flow path following the completion of the measurement of chemical concentrations in the portion of the plating solution.

6. The system of claim 1, wherein the plumbing system comprises a fourth flow path for draining liquid from the sampling reservoir out of the plumbing system.

7. The system of claim 6, wherein the system controller further controls using the fourth flow path for discarding one of de-ionized water and standard solution.

8. The system of claim 1, further comprising a temperature controller for maintaining the temperature of liquid inside the sampling reservoir within a predetermined range.

9. The system of claim 8, wherein the predetermined range is from about 18 degrees Celsius to about 22 degrees Celsius.

10. The system of claim 1, further comprising a temperature controller for maintaining the temperature of liquid inside the sampling reservoir at about 20 degrees Celsius.

11. The system of claim 1, wherein the electrical noise is generated by application of voltage in the one or more plating cells.

12. The plumbing system of claim 1, wherein the plumbing system comprises one or more bi-directional flow paths between the one or more plating cell reservoirs and the chemical analyzer.

13. An electrochemical plating system, comprising:

one or more plating cell reservoirs for storing plating solution;

a chemical analyzer in fluidic communication with the one or more plating cell reservoirs, wherein the chemical analyzer is configured to measure chemical concentrations of the plating solution;

a sampling reservoir coupled to the chemical analyzer, wherein the sampling reservoir is configured to hold a portion of the plating solution;

a plumbing system configured to facilitate the fluidic communication between the one or more plating cell reservoirs and the chemical analyzer and to substantially isolate the chemical analyzer from electrical noise generated by one or more plating cells of the one or more plating cell reservoirs, wherein the plumbing system comprises;

(i) at least one valve that allows the portion of the plating solution to flow from the one or more plating cell reservoirs to the sampling reservoir, when the at least one valve is in an open position;

(ii) a first flow path for delivering the portion of the plating solution from the one or more plating cell reservoirs to the sampling reservoir;

(iii) a second flow path for circulating the portion of the plating solution through the chemical analyzer;

(iv) a third flow path for returning the portion of the plating solution to the one or more plating cell reservoirs; and

(v) a fourth flow path for draining liquid from the sampling reservoir out of the plumbing system; and

a system controller, wherein the system controller comprises a microprocessor, and wherein the system controller is configured to receive inputs and use the inputs to control;

(i) circulating a portion of a plating solution through the chemical analyzer; and

(ii) switching the at least one valve to a closed position once the sampling reservoir is filled with the portion of the plating solution to substantially isolate the chemical analyzer from the electrical noise generated by the one or more plating cells.