Method and system for arc suppression in a plasma processing system

• US 7,199,327 B2
• Filed: 06/27/2003
• Issued: 04/03/2007
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Moroz, Paul, Strang, Eric
• Primary Examiner(s): Paschall; Mark
• Application Number:
  US10/512,862
• Publication Number:
  US 20060081564A1
• Time in Patent Office: 1,376 Days
• Field of Search: 219/121.4, 219/121.41, 219/121.54, 219/121.43, 156/349.24, 156/345.48
• US Class Current: 219/121.41
• CPC Class Codes: H01J 2237/0206 Extinguishing, preventing or controlling unwanted discharges
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32706 Polarising the substrate
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge

Abstract

An arc suppression system for plasma processing comprising at least one sensor coupled to the plasma processing system, and a controller coupled to the at least one sensor. The controller provides at least one algorithm for determining a state of plasma in contact with a substrate using at least one signal generated from the at least one sensor and controlling a plasma processing system in order to suppress an arcing event. When voltage differences between sensors exceed a target difference, the plasma processing system is determined to be susceptible to arcing. During this condition, an operator is notified, and decision can be made to either continue processing, modify processing, or discontinue processing.

Claims

1. A plasma processing system, comprising:

a process reactor configured to facilitate formation of plasma; and

an arc suppression system coupled to said process reactor, said arc suppression system comprising at least one sensor configured to produce at least one signal related to said plasma; and

a controller coupled to said at least one sensor, wherein said controller is configured to determine a state of a probability of occurrence of arcing in said plasma processing system using said at least one signal and to control said plasma processing system according to said state to reduce the probability of occurrence of an arcing event.

2. The plasma processing system as recited in claim 1, wherein said at least one sensor comprises at least one antenna embedded within at least one of a substrate holder, a chamber wall and a chamber liner.

3. The plasma processing system as recited in claim 2, wherein said at least one antenna comprises at least one antenna electrode and an antenna lead coupled to each antenna electrode of the at least one antenna electrode.

4. The plasma processing system as recited in claim 3, wherein said antenna lead comprises an inner conductive element and an inner dielectric element.

5. The plasma processing system as recited in claim 4, wherein said antenna lead further comprises an outer conductive element and an outer dielectric element.

6. The plasma processing system as recited in claim 2, further comprising an electrical measurement device configured to connect to said at least one antenna.

7. The plasma processing system as recited in claim 2, said at least one antenna being embedded within said substrate holder which comprises at least one of a RF biasable electrode, an electrostatic clamping device, an outer shield, an isolation ring, a focus ring, a dielectric ring, and a shield ring.

8. The plasma processing system as recited in claim 2, wherein said substrate holder comprises at least one of an electrostatic clamping system and a backside gas system.

9. The plasma processing system as recited in claim 6, wherein the electrical measurement device comprises a voltage probe.

10. The plasma processing system as recited in claim 1, wherein said at least one signal related to said plasma is at least one of a time varying voltage signal and a time varying voltage amplitude.

11. The plasma processing system as recited in claim 1, wherein said at least one signal related to said plasma comprises a filtered signal.

12. The plasma processing system as recited in claim 11, wherein said filtered signal is derived from said at least one signal using at least one of a low-pass filter, a high-pass filter, and a band-pass filter.

13. The plasma processing system as recited in claim 1, wherein said at least one sensor comprises a plurality of sensors and said controller is configured to determine a state of a probability of occurrence of arcing at different regions in said plasma processing system.

14. The plasma processing system as recited in claim 1, wherein said controlling said plasma processing system according to said state of said plasma in order to suppress the arcing event comprises performing at least one of alerting an operator, continuing a process, modifying a process and discontinuing a process.

15. An arc suppression system comprising:

at least one sensor configured to couple to a plasma processing system; and

a controller configured to execute at least one algorithm for determining a state of a probability of occurrence of arcing in said plasma processing system using said at least one signal related to said plasma processing system and controlling said plasma processing system according to said state in order to reduce the probability of occurrence of an arcing event.

16. The arc suppression system as recited in claim 15, wherein said at least one sensor comprises at least one antenna embedded within at least one of a substrate holder, a chamber wall and a chamber liner.

17. The plasma processing system as recited in claim 16, wherein said at least one antenna comprises at least one antenna electrode and an antenna lead coupled to each antenna electrode of the at least one antenna electrode.

18. The arc suppression system as recited in claim 17, wherein said antenna lead comprises an inner conductive element and an inner dielectric element.

19. The arc suppression system as recited in claim 18, wherein said antenna lead further comprises an outer conductive element and an outer dielectric element.

20. The arc suppression system as recited in claim 16, further comprising an electrical measurement device configured to connect to said at least one antenna.

21. The arc suppression system as recited in claim 15, wherein said at least one antenna embedded with said substrate holder comprises at least one antenna embedded in at least one of a RF biasable electrode, an electrostatic clamping device, an outer shield, an isolation ring, a focus ring a dielectric ring, and a shield ring.

22. The arc suppression system as recited in claim 16, wherein said substrate holder comprises at least one of an electrostatic clamping system and a backside gas system.

23. The arc suppression system as recited in claim 20, wherein said electrical measurement device comprises a voltage probe.

24. The arc suppression system as recited in claim 15, wherein said at least one signal related to said plasma is at least one of a time varying voltage signal and a time varying voltage amplitude.

25. The arc suppression system as recited in claim 15, wherein said at least one signal related to said plasma comprises a filtered signal.

26. The arc suppression system as recited in claim 25, further comprises at least one of a low-pass filter, a high-pass filter, and a band-pass filter configured to derive said filtered signal from said at least one signal.

27. The arc suppression system as recited in claim 15, wherein said at least one sensor comprises a plurality of sensors and said controller is configured to determine a state of a probability of occurrence of arcing at different regions in said plasma processing system.

28. The arc suppression system as recited in claim 15, wherein said controlling said plasma processing system according to said state of said plasma in order to suppress an arcing event comprises performing at least one of alerting an operator, continuing a process, modifying a process and discontinuing a process.

29. A method for suppressing arcing in a plasma processing system utilizing an arc suppression system comprising at least one sensor coupled to said plasma processing system, and a controller coupled to said at least one sensor, the method comprising:

measuring at least one signal related to said plasma processing system using said at least one sensor;

determining at least one difference signal between said at least one signal and a reference signal;

comparing said at least one difference signal to a target difference;

determining a state of a probability of occurrence of arcing in said plasma processing system from said comparing; and

controlling said plasma processing system in order to reduce the probability of occurrence of an arcing event,

wherein said at least one signal is measured using at least one sensor that comprises at least one antenna embedded within at least one of a substrate holder, a chamber wall and a chamber liner.

30. The method as recited in claim 29, wherein said measuring further comprises filtering said at least one signal.

31. The method as recited in claim 30, wherein said filtering comprises using at least one of a low-pass filter, a high-pass filter, and a band-pass filter.

32. The method as recited in claim 30, wherein said filtering provides at least one of a filtered time varying signal and a filtered time varying amplitude.

33. The method as recited in claim 29, wherein said determining at least one difference signal between said at least one signal and said reference signal comprises subtracting said reference signal from said at least one signal.

34. The method as recited in claim 29, wherein said at least one difference signal comprises at least one of a difference between an instantaneous value of said at least one signal measured at an instant in time and said reference signal, an amplitude of said at least one signal and said reference signal, an instantaneous value of a filtered said at least one signal measured at an instant in time and said reference signal, and amplitude of a filtered said at least one signal and said reference signal.

35. The method as recited in claim 29, wherein said measuring comprises measuring a plurality of signals at different regions of the plasma processing system using a plurality of respective sensors, and said determining comprises determining a state of a probability of an occurrence of arcing at said different regions in said plasma processing system.

36. The method as recited in claim 29, wherein said probability for the occurrence of arcing in said plasma processing system comprises at least one of a high probability and a low probability.

37. The method as recited in claim 29, wherein said method further comprises controlling said plasma processing system according to said state of said plasma processing system in order to suppress an arcing event.

38. The method as recited in claim 33, wherein said controlling comprises at least one of notifying an operator, continuing a process, discontinuing a process, and modifying a process.

39. The method as recited in claim 38, wherein said modifying a process comprises adjusting at least one of a process pressure, a substrate holder RF bias, an electrostatic clamp electrode bias, a backside gas pressure, and a process gas flow rate.

40. The method as recited in claim 29, wherein said reference signal comprises a ground potential.

41. A method for suppressing arcing in a plasma processing system utilizing an arc suppression system comprising at least one sensor coupled to said plasma processing system, and a controller coupled to said at least one sensor, the method comprising:

measuring a first signal related to said plasma processing system using a first sensor;

measuring a second signal related to said plasma processing system using a second sensor;

determining a difference signal between said first signal and said second signal;

comparing said difference signal to a target difference;

determining a state of a probability of occurrence of arcing in said plasma processing system based on said comparing; and

controlling said plasma processing system in order to reduce the probability of occurrence of an arcing event.

42. The method as recited in claim 41, wherein said first signal is measured using at least one sensor that comprises at least one antenna embedded within at least one of a substrate holder, a chamber wall and a chamber liner.

43. The method as recited in claim 41, wherein said measuring the first signal further comprises filtering said first signal.

44. The method as recited in claim 43, wherein said filtering comprises using at least one of a low-pass filter, a high-pass filter, and a band-pass filter.

45. The method as recited in claim 43, wherein said filtering provides at least one of a first filtered time varying signal and a first filtered time varying amplitude.

46. The method as recited in claim 41, wherein said second signal is measured using at least one sensor that comprises at least one antenna embedded within at least one of a substrate holder, a chamber wall and a chamber liner.

47. method as recited in claim 41, wherein said measuring the second signal further comprises filtering said second signal.

48. The method as recited in claim 47, wherein said filtering comprises using at least one of a low-pass filter, a high-pass filter and a band-pass filter.

49. The method as recited in claim 47, wherein said filtering provides at least one of a second filtered time varying signal and a second filtered time varying amplitude.

50. The method as recited in claim 41, wherein said determining a difference signal between said first signal and said second signal comprises subtracting said first signal from said second signal.

51. The method as recited in claim 41, wherein said determining comprises determining a state of the probability for the occurrence of arcing at different regions in said plasma processing system.

52. The method as recited in claim 51, wherein said probability for the occurrence of arcing in said plasma processing system comprises at least one of a high probability and a low probability.

53. The method as recited in claim 43, wherein said method further comprises controlling said plasma processing system according to said state of said plasma processing system in order to suppress an arcing event.

54. The method as recited in claim 53, wherein said controlling comprises at least one of notifying an operator, continuing a process, discontinuing a process, and modifying a process.

55. The method as recited in claim 54, wherein said modifying a process comprises adjusting at least one of a process pressure, a substrate holder RF bias, an electrostatic clamp electrode bias, a backside gas pressure, and a process gas flow rate.

56. The method as recited in claim 41, wherein said measuring a first signal and said measuring a second signal are performed at substantially the same time.

57. The method as recited in claim 41, wherein said measuring a first signal and said measuring a second signal are performed at substantially different times.

58. The method as recited in claim 41, wherein said measuring a first signal corresponds to a first location and said measuring a second signal corresponds to a second location.

59. The method as recited in claim 58, wherein said first location comprises at least one of a substrate center, a substrate edge, and a focus ring;

and said second location comprises at least one of a substrate center, a substrate edge, and a focus ring.

60. A plasma processing system, comprising:

a plasma reactor configured to facilitate formation of plasma; and

means for arc suppression coupled to plasma reactor, said means for arc suppression comprising means for producing at least one signal related to said plasma; and

means for controlling coupled to said at least one sensor, wherein said means for controlling determines a state of a probability of occurrence of arcing in said plasma processing system using said at least one signal and controls said plasma processing system according to said state to reduce the probability of occurrence of an arcing event.

61. The plasma processing system as recited in claim 60, wherein said means for producing at least one signal comprises at least one antenna embedded within at least one of a substrate holder, a chamber wall and a chamber liner.

62. The plasma processing system as recited in claim 60, further comprising an electrical measurement device.

63. The plasma processing system as recited in claim 62, wherein the electrical measurement device comprises a voltage probe.

64. The plasma processing system as recited in claim 60, further comprising housing means for protecting the means for producing the at least one signal from the plasma of the plasma reactor.