Capacitively-coupled electrostatic (CCE) probe arrangement for detecting strike step in a plasma processing chamber and methods thereof

• US 8,164,349 B2
• Filed: 07/07/2009
• Issued: 04/24/2012
• Est. Priority Date: 07/07/2008
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Booth, Jean-Paul, Keil, Douglas L.
• Primary Examiner(s): NGUYEN, HOAI AN D
• Application Number:
  US12/498,936
• Publication Number:
  US 20100006417A1
• Time in Patent Office: 1,022 Days
• Field of Search: 324/686, 324/658, 324/649, 324/600, 324/715, 324/716, 324/522, 324/76.69, 324/555, 324/76.11, 324/762.01, 702/1, 702/57, 702/64, 702/127, 340/664, 340/660, 361/79, 361/86, 361/87
• US Class Current: 324/658
• CPC Class Codes: H05H 1/0012 using electromagnetic or particle radiation, e.g. interferometry
• CPC Class Codes: H05H 1/0081 by electric means

Abstract

A method for identifying a stabilized plasma within a processing chamber of a plasma processing system is provided. The method includes executing a strike step within the processing chamber to generate a plasma. The strike step includes applying a substantially high gas pressure within the processing chamber and maintaining a low radio frequency (RF) power within the processing chamber. The method also includes employing a probe head to collect a set of characteristic parameter measurements during the strike step, the probe head being on a surface of the processing chamber, wherein the surface is within close proximity to a substrate surface. The method further includes comparing the set of characteristic parameter measurements against a pre-defined range. If the set of characteristic parameter measurements is within the pre-defined range, the stabilized plasma exists.

Claims

1. A method for identifying a stabilized plasma within a processing chamber of a plasma processing system, comprising:

executing a strike step within said processing chamber to generate a plasma, wherein said strike step includes

applying a substantially high gas pressure within said processing chamber, and

maintaining a low radio frequency (RF) power within said processing chamber;

employing a probe head to collect a set of characteristic parameter measurements during said strike step, said probe head being on a surface of said processing chamber, wherein said surface is within close proximity to a substrate surface; and

comparing said set of characteristic parameter measurements against a pre-defined range, if said set of characteristic parameter measurements is within said pre-defined range, said stabilized plasma exists.

2. The method of claim 1 wherein said probe head is a capacitively-coupled electrostatic (CCE) probe.

3. The method of claim 2 wherein said probe head is a small device, wherein a plasma-facing surface of said probe head is made from a material similar to other plasma-facing components of said processing chamber.

4. The method of claim 1 wherein said set of characteristic parameter measurements is a set of ion flux measurement.

5. The method of claim 1 wherein said set of characteristic parameter measurements is a set of electron temperature measurements.

6. The method of claim 1 wherein said set of characteristic parameter measurements is a set of floating potential measurements.

7. The method of claim 1 wherein if said set of characteristic parameter measurements is not within said predefined range, said plasma is not stabilized and corrective actions is applied.

8. An arrangement for identifying a stabilized plasma within a processing chamber of a plasma processing system, comprising:

a substrate, wherein said substrate is positioned on a lower electrode within said processing chamber;

a radio frequency (RF) power source, wherein said RF power source is being applied at a low RF power within said processing chamber;

a gas delivery system, wherein a gas is delivered into said processing chamber to interact with said RF power to create a plasma;

a pressure module, wherein said pressure module is applied at a substantially high force within said processing chamber;

a probe arrangement, wherein said probe arrangement includes a plasma-facing sensor and is disposed on a surface of said processing chamber, said surface is within close proximity to a surface of said substrate, wherein said probe arrangement is configured at least to collect a set of characteristic parameter measurements during a strike step; and

a detection module, wherein said detection module is configured to compare said set of characteristic parameter measurements against a pre-defined range, if said set of characteristic parameter measurements is within said pre-defined range, said stabilized plasma exists.

9. The arrangement of claim 8 wherein said plasma-facing sensor is a capacitively-coupled electrostatic (CCE) probe head.

10. The arrangement of claim 9 wherein said plasma-facing sensor is a small device, wherein a plasma-facing surface of said plasma-facing sensor is made from a material similar to other plasma-facing components of said processing chamber.

11. The arrangement of claim 8 wherein said set of characteristic parameter measurements is a set of ion flux measurement.

12. The arrangement of claim 8 wherein said set of characteristic parameter measurements is a set of electron temperature measurements.

13. The arrangement of claim 8 wherein said set of characteristic parameter measurements is a set of floating potential measurements.

14. The arrangement of claim 8 wherein said detection module is a software algorithm.

15. The arrangement of claim 8 wherein if said detection module is unable to determine said stabilized plasma, corrective actions is applied.

16. An article of manufacture comprising a program storage medium having computer readable code embodied therein, said computer readable code being configured for identifying a stabilized plasma within a processing chamber of a plasma processing system, comprising:

code for executing a strike step within said processing chamber to generate a plasma, wherein said strike step includes

code for applying a substantially high gas pressure within said processing chamber, and

code for maintaining a low radio frequency (RF) power within said processing chamber;

code for collecting a set of characteristic parameter measurements during said strike step by using a probe head, said probe head being on a surface of said processing chamber, wherein said surface is within close proximity to a substrate surface; and

code for comparing said set of characteristic parameter measurements against a pre-defined range, if said set of characteristic parameter measurements is within said pre-defined range, said stabilized plasma exists.

17. The article of manufacture of claim 16 wherein said probe head is a capacitively-coupled electrostatic (CCE) probe.

18. The article of manufacture of claim 16 wherein said set of characteristic parameter measurements is one of a set of ion flux measurement, a set of electron temperature measurements, and a set of floating potential measurements.

19. The article of manufacture of claim 16 wherein if said set of characteristic parameter measurements is not within said pre-defined range, said plasma is not stabilized and corrective actions is applied.

20. The article of manufacture of claim 16 wherein said code for comparing of said set of characteristic parameter measurement against said pre-defined range is performed by a detection module.