System and method for point of use delivery, control and mixing chemical and slurry for CMP/cleaning system

• US 20040199293A1
• Filed: 04/19/2004
• Published: 10/07/2004
• Est. Priority Date: 02/15/2002
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Nguyen, Tuan, Zhou, Ren, Pham, Xuyen, Quach, Vien
• Granted Patent: US 7,054,719 B2
• Time in Patent Office: Days
• US Class Current: 700/265
• CPC Class Codes: G05D 11/132 by controlling the flow of the individual components G05D11/133 takes precedence

Abstract

A method of mixing two or more chemicals such as for a CMP system. The method includes delivering a first chemical to a first inlet port of a point of use mixer at a first flow rate, delivering a second chemical to a second inlet port of the point of use mixer at a second flow rate, controlling the flow of the first and second chemicals into the mixer upon demand for a mixture of the first and second chemicals and balancing the flow of the first and second chemicals into the mixer. The mixture can also be output such as to a CMP process. A system for mixing two or more chemicals is also described.

Claims

1. A method of mixing two or more chemicals for a CMP system comprising:

delivering a first chemical to a first inlet port of a point of use mixer at a first flow rate;

delivering a second chemical to a second inlet port of the point of use mixer at a second flow rate;

controlling the flow of the first and second chemicals into the mixer upon demand for a mixture of the first and second chemicals;

balancing the flow of the first and second chemicals into the mixer; and

outputting the mixture to a CMP process.

2. The method of claim 1, wherein the mixer has an outlet port that is sized proportional to the first inlet port and the second inlet port.

3. The method of claim 1, wherein the mixer is a radial mixer.

4. The method of claim 3, wherein the first inlet port and the second inlet port are substantially equidistant from the outlet port.

5. The method of claim 1, wherein outputting the mixture includes providing a substantially constant flow of the mixture to an outlet point.

6. The method of claim 5, wherein providing a substantially constant flow of the mixture to an outlet point includes providing a sufficient backpressure to a flow controller that is upstream of the outlet point.

7. The method of claim 6, wherein providing a sufficient backpressure to a flow controller that is upstream of the outlet point includes selecting a size of the outlet point according to the flow rate of the mixture.

8. The method of claim 1, wherein controlling the flow of the first and the second chemicals into the mixer includes controlling the flow rate of the mixer according to an aspect of the mixture.

9. A CMP system comprising:

a mixer having an outlet coupled to an outlet point;

a first chemical supply capable of delivering a first chemical at a first flow rate to a first inlet port of a mixer;

a second chemical supply capable of delivering a second chemical at a second flow rate to a second inlet port of a mixer;

an outlet flow rate sensor coupled to the mixer outlet; and

a controller configured to receive signals from the outlet flow sensor and to produce control signals for the first and second chemical supplies and configured to cause a substantially constant flow of a mixture of the first and second chemicals upon a demand from a CMP process.

10. The system of claim 9, wherein the mixer outlet port that is sized proportional to the first inlet port and the second inlet port.

12. The system of claim 9, wherein the mixer is a radial mixer.

13. The system of claim 12, wherein the first inlet port and the second inlet port are substantially equidistant from the outlet port.

14. The system of claim 9, wherein the outlet point is sized to provide a sufficient backpressure to a flow controller that is upstream of the outlet point.

15. The system of claim 14, wherein the outlet point is sized according to the flow rate of the mixture.

16. The system of claim 9, wherein the outlet point includes more than one outlet points.

17. The system of claim 16, wherein each one of the more than one outlet points have the same size.

18. The system of claim 16, wherein each one of the more than one outlet points have the different sizes.

19. The system of claim 9, further comprising:

a mixture sensor coupled to the output of the mixer and to the controller.

20. The system of claim 18, wherein the mixture sensor is a pH sensor.

21. A mixing system comprising:

a radial mixer having an outlet coupled to an outlet point;

a first chemical supply capable of delivering a first chemical at a first flow rate to a first inlet port of a mixer;

a second chemical supply capable of delivering a second chemical at a second flow rate to a second inlet port of a mixer;

an outlet flow sensor coupled to the mixer outlet, the mixer outlet having a size that is determined by a desired outlet flow rate; and

a controller configured to receive signals from the outlet flow sensor and to produce control signals for the first and second chemical supplies and configured to cause a substantially constant flow of a mixture of the first and second chemicals upon a demand.