Monitoring erosion of system components by optical emission

• US 6,894,769 B2
• Filed: 12/31/2002
• Issued: 05/17/2005
• Est. Priority Date: 12/31/2002
• Status: Expired due to Fees

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Strang, Eric J., Ludviksson, Audunn
• Primary Examiner(s): Smith, Zandra
• Assistant Examiner(s): GEISEL, KARA E
• Application Number:
  US10/331,456
• Publication Number:
  US 20040125360A1
• Time in Patent Office: 868 Days
• Field of Search: 356 72- 73, 356316-317, 356/311, 2504581-4611
• US Class Current: 356/72
• CPC Class Codes: G01N 2021/8416 and process controlling, not otherwise provided for
• CPC Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/32963 End-point detection
• CPC Class Codes: H01J 37/32972 Spectral analysis
• CPC Class Codes: H01J 37/3299 Feedback systems

Abstract

A method and system are provided for monitoring erosion of system components in a plasma processing system. The system components contain emitters that are capable of producing characteristic fluorescent light emission when exposed to a plasma. The method utilizes optical emission to monitor fluorescent light emission from the emitters for determining system component status. The method can evaluate erosion of system components in a plasma, by monitoring fluorescent light emission from the emitters. Consumable system components that can be monitored using the method include rings, shields, electrodes, baffles, and liners.

Claims

1. A method of monitoring erosion of a system component in a plasma processing system, the method comprising:

exposing a system component to a plasma, the system component containing an emitter capable of fluorescent light emission when excited by light from the plasma; and

monitoring the fluorescent light emission from the plasma processing system during a process to determine erosion of the system component.

2. The method according to claim 1, wherein the fluorescent light emission relates to an amount of erosion of the system component.

3. The method according to claim 1, wherein the system component comprises a consumable part.

4. The method according to claim 1, wherein the system component comprises at least one of a ring, a shield, an electrode, a baffle, and a liner.

5. The method according to claim 1, wherein the emitter comprises at least one material having fluorescent properties when excited by excited gas species produced in the plasma.

6. The method according to claim 1, wherein the monitoring comprises using an optical monitoring system to detect the fluorescent light emission.

7. The method according to claim 6, wherein the monitoring further comprises determining if the intensity level of the fluorescent emission exceeds a threshold value.

8. The method according to claim 6, wherein the monitoring further comprises identifying the system component from the wavelength of the fluorescent light emission.

9. The method according to claim 6, wherein the monitoring further comprises measuring an intensity level of the fluorescent emission to arrive at a determination of whether the component needs to be replaced, and based on the determination, either continuing with the process or stopping the process.

10. A method of monitoring system component status in a plasma processing system, the method comprising:

exposing a system component to a plasma, the system component containing an emitter capable of fluorescent light emission when excited by light from the plasma; and

monitoring fluorescent light emission from the plasma processing system during a process, the monitoring including using an optical monitoring system to detect the wavelength and the intensity level of the fluorescent light emission, identifying the system component from the wavelength of the fluorescent light emission, and arriving at a determination of erosion level of the system component.

11. A plasma processing system, comprising:

a plasma processing chamber;

a plasma source configured to create a plasma from a process gas;

a system component containing an emitter capable of fluorescent light emission when excited by light from a plasma;

an optical monitoring system for monitoring light emission from the plasma processing chamber during processing to monitor erosion level of the system component; and

a controller configured to control the plasma processing system.

12. The system according to claim 11, wherein the system component comprises a consumable part.

13. The system according to claim 11, wherein the system component comprises at least one of a ring, a shield, an electrode, a baffle, and a liner.

14. The system according to claim 11 wherein the system component is fabricated from least one of silicon, quartz, alumina, carbon, silicon carbide, aluminum, and stainless steel.

15. The system according to claim 11, wherein the emitter comprises at least one material having fluorescent properties when excited by excited gas species produced in the plasma.

16. The system according to claim 15, wherein the at least one material comprises a phosphor material.

17. The system according to claim 11, wherein the emitter comprises at least one of Y₂O₃:

Eu, Y₂O₂S;

Eu, Y₂O₂S;

Tb, Y₂O₂S;

EuTb, ZnS;

Cu, ZnS;

Al, ZnS;

CuAl, SrGa₂S₄;

Ce, ZnS;

Ag, ZnS;

Au, ZnS;

Cl, ZnS;

AgAu, ZnS;

AgCl, ZnS;

AuCl, ZnS;

AgAuCl, and SrGa₂S₄;

Ce.

18. The system according to claim 11, wherein the system component further comprises a protective barrier.

19. The system according to claim 11, wherein the protective barrier comprises at least one of Y₂O₃, Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, DyO₃, SiO₂, MgO, Al₂O₃, ZnO, SnO₂, and In₂O₃.

20. The system according to claim 18, wherein the protective barrier is transparent.

21. The system according to claim 11, wherein the plasma source comprises an inductive coil.

22. The system according to claim 11, wherein the plasma source comprises a plate electrode.

23. The system according to claim 11, wherein the plasma source comprises an ECR source.

24. The system according to claim 11, wherein the plasma source comprises a Helicon wave source.

25. The system according to claim 11, wherein the plasma source comprises a surface wave source.

26. A plasma processing system, comprising:

a plasma processing chamber;

a plasma source configured to create a plasma from a process gas;

a system component containing an emitter capable of fluorescent light emission when excited by light from a plasma;

an optical monitoring system for monitoring light emission from the plasma processing chamber during processing to monitor erosion level of the system component;

wherein the optical monitoring system is further configured to identify the system component from the wavelength of the fluorescent light emission, to determine if the intensity level of the fluorescent emission exceeds a threshold value, to determine if the system component needs to be replaced, and based on the determination, either continue with the process or stop the process; and

a controller configured to control the plasma processing system.

27. A monitorable consumable system component, comprising:

a component element; and

an emitter coupled to the component element, the emitter being capable of fluorescent light emission when excited by light from a plasma, wherein the light emission is used to monitor erosion level of the system component.

28. The consumable system component according to claim 27, wherein the component element comprises a ring, a shield, an electrode, a baffle, or a liner.

29. The consumable system component according to claim 27, wherein the component element is a focus ring.

30. The consumable system component according to claim 27, wherein the component element is an electrode plate.

31. The consumable system component according to claim 27, wherein the component element is a deposition shield.

32. The consumable system component according to claim 27, wherein the component element is fabricated from least one of silicon, quartz, alumina, carbon, silicon carbide, aluminum, and stainless steel.

33. The consumable system component according to claim 27, wherein the emitter is fully encapsulated by the component element.

34. The consumable system component according to claim 27, wherein the emitter is partially encapsulated by the component element.

35. The consumable system component according to claim 27, wherein the emitter comprises at least one material having fluorescent properties when excited by excited gas species produced in a plasma.

36. The consumable system component according to claim 27, wherein the light emission from the emitter allows for identifying the consumable system component.

37. The consumable system component according to claim 27, wherein the emitter comprises a phosphor material.

38. The consumable system component according to claim 27, wherein the emitter comprises at least one of Y₂O₃:

Eu, Y₂O₂S;

Eu, Y₂O₂S;

Tb, Y₂O₂S;

EuTb, ZnS;

Cu, ZnS;

Al, ZnS;

CuAl, SrGa₂S₄;

Ce, ZnS;

Ag, ZnS;

Au, ZnS;

Cl, ZnS;

AgAu, ZnS;

AgCl, ZnS;

AuCl, ZnS;

AgAuCl, and SrGa₂S₄;

Ce.

39. The consumable system component according to claim 27, wherein the system component further comprises a protective barrier.

40. The consumable system component according to claim 39 wherein the protective barrier comprises at least one of Y₂O₃, Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, CeO₂, Eu₂O₃, DyO₃, SiO₂, MgO, Al₂O₃, ZnO, SnO₂, and In₂O₃.

41. The consumable system component according to claim 39 wherein the protective barrier comprises at least one material having fluorescent properties when excited by light produced in a plasma.

42. The consumable system component according to claim 39 wherein the protective barrier comprises at least one material having fluorescent properties when excited by excited gas species produced in a plasma.

43. The consumable system component according to claim 39 wherein the protective barrier is transparent.