Corrugated plasma trap arrangement for creating a highly efficient downstream microwave plasma system

• US 7,554,053 B2
• Filed: 12/23/2005
• Issued: 06/30/2009
• Est. Priority Date: 12/23/2005
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Wang, Ing-Yann Albert, Kamarehi, Mohammad
• Primary Examiner(s): Hoang; Tu B
• Assistant Examiner(s): Ralis; Stephen J
• Application Number:
  US11/317,874
• Publication Number:
  US 20070145020A1
• Time in Patent Office: 1,285 Days
• Field of Search: 118/723.MW, 118/723.ME, 118/723.MR, 156/345.35, 156/345.36, 156/345.41, 219/695, 219/696, 219/746, 219/121.4, 219/121.41, 219741-743, 219/699
• US Class Current: 219/121.41
• CPC Class Codes: H01J 37/32229 Waveguides
• CPC Class Codes: H01J 37/32266 Means for controlling power transmitted to the plasma
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence

Abstract

A plasma system is disclosed. The plasma system includes a microwave waveguide assembly having a longitudinal axis parallel with a first axis. The plasma system also includes a plasma tube assembly intersecting the microwave waveguide assembly. The plasma tube assembly has a longitudinal axis parallel with a second axis that is substantially orthogonal with the first axis. The plasma tube assembly also has a plasma-sustaining region defined by an upstream plurality of plasma traps and a downstream plurality of plasma traps.

Claims

1. A plasma system comprising:

a microwave waveguide assembly; and

a plasma tube assembly intersecting said microwave waveguide assembly, said plasma tube assembly having a plasma-sustaining region defined by an upstream plurality of plasma traps and a downstream plurality of plasma traps,

wherein a first plasma trap among at least one of said upstream plurality of plasma traps and said downstream plurality of plasma traps includes a first downstream corrugated outer surface and a first upstream corrugated outer surface disposed at an opposite side to said first downstream corrugated outer surface, said first plasma trap further including a first plurality of corrugated peaks protruding, in a first direction parallel to said plasma tube assembly, outward from said first downstream corrugated outer surface thereby forming said first downstream corrugated outer surface, said first plasma trap further including a second plurality of corrugated peaks protruding, in a second direction parallel to said plasma tube assembly and said first plurality of corrugated peaks, outward from said first upstream corrugated outer surface thereby forming said first upstream corrugated outer surface, and

a second plasma trap among at least one of said upstream plurality of plasma traps and said downstream plurality of plasma traps includes a second upstream corrugated outer surface and a second downstream corrugated outer surface disposed at an opposite side to said second upstream outer surface, said second plasma trap further including a third plurality of corrugated peaks protruding, in said first direction parallel to said plasma tube assembly, outward from said second downstream corrugated outer surface thereby forming said second downstream corrugated outer surface, said second plasma trap further including a fourth plurality of corrugated peaks protruding, in said second direction parallel to said plasma tube assembly and said third plurality of corrugated peaks, outward from said second upstream corrugated outer surface thereby forming said second upstream corrugated outer surface, said second upstream corrugated outer surface facing said first downstream corrugated outer surface.

2. The plasma system of claim 1 wherein said first plurality of corrugated peaks includes at least a first corrugated peak and a second corrugated peak, said first corrugated peak surrounding said plasma tube assembly, said second corrugated peak surrounding said first corrugated peak.

3. The plasma system of claim 1 wherein said downstream plurality of plasma traps includes at least a downstream outer plasma trap and a downstream inner plasma trap, said downstream outer plasma trap being disposed downstream relative to said downstream inner plasma trap.

4. The plasma system of claim 3 further including a downstream cooling manifold, said downstream cooling manifold being disposed in at least one of a first assembly arrangement and a second assembly arrangement relative to said downstream outer plasma trap, said first assembly arrangement being characterized by having substantially no air gap between an upstream-facing surface of said downstream cooling manifold and a downstream-facing surface of said downstream outer plasma trap, said second assembly arrangement being characterized by said downstream cooling manifold being disposed adjacent to said downstream outer plasma trap.

5. The plasma system of claim 4 wherein said downstream cooling manifold is disposed in said first assembly arrangement relative to said downstream outer plasma trap.

6. The plasma system of claim 4 wherein said downstream cooling manifold is disposed in said second assembly arrangement relative to said downstream outer plasma trap.

7. The plasma system of claim 3 wherein said downstream outer plasma trap is formed of a first hollow center electrically conductive disk surrounding a passage within said plasma tube assembly, wherein a second hollow center electrically conductive disk is disposed upstream of said first hollow center electrically conductive disk, said second hollow center electrically conductive disk also surrounding said passage within said plasma tube assembly, and a first interstitial region is disposed between said first hollow center electrically conductive disc and said second hollow center electrically conductive disc.

8. The plasma system of claim 7 wherein said first interstitial region forms an air gap.

9. The plasma system of claim 7 wherein said first interstitial region is formed of a solid material other than air.

10. The plasma system of claim 7 wherein said downstream inner plasma trap is formed of said second hollow center electrically conductive disk, wherein a third hollow center electrically conductive disk is disposed upstream relative to said second hollow center electrically conductive disk, and a second interstitial region is disposed between said second hollow center electrically conductive disc and said third hollow center electrically conductive disc.

11. The plasma system of claim 10 wherein said second interstitial region forms an air gap.

12. The plasma system of claim 10 wherein said second interstitial region is formed of a solid material other than air.

13. The plasma system of claim 3 wherein said downstream outer plasma trap is formed of a first solid center electrically conductive disk surrounding a passage within said plasma tube assembly, wherein a second solid center electrically conductive disk is disposed upstream of said first solid center electrically conductive disk, said second solid center electrically conductive disk also surrounding said passage within said plasma tube assembly, and a first interstitial region is disposed between said first solid center electrically conductive disc and said second solid center electrically conductive disc.

14. The plasma system of claim 13 wherein said first interstitial region forms an air gap.

15. The plasma system of claim 13 wherein said first interstitial region is formed of a solid material other than air.

16. The plasma system of claim 13 wherein said downstream inner plasma trap is formed of said second solid center electrically conductive disk, wherein a third solid center electrically conductive disk is disposed upstream relative to said second solid center electrically conductive disk, and a second interstitial region is disposed between said second solid center electrically conductive disc and said third solid center electrically conductive disc.

17. The plasma system of claim 16 wherein said second interstitial region forms an air gap.

18. The plasma system of claim 16 wherein said second interstitial region is formed of a solid material other than air.

19. The plasma system of claim 3 further including an upstream cooling manifold, said upstream cooling manifold being disposed such that there exists substantially no air gap between a downstream-facing surface of said upstream cooling manifold and an upstream-facing surface of an upstream outer plasma trap among said upstream plurality of plasma traps.

20. The plasma system of claim 3 further including an upstream cooling manifold, said upstream cooling manifold being disposed adjacent to an upstream outer plasma trap among said upstream plurality of plasma traps.

21. The plasma system of claim 1 wherein said microwave guide assembly includes a sliding short configured for tuning said microwave guide assembly.

22. A plasma system comprising:

a microwave waveguide assembly; and

a plasma tube assembly intersecting said microwave waveguide assembly, said plasma tube assembly having a plasma-sustaining region defined by an upstream plasma trap set and downstream plasma trap set disposed downstream relative to said upstream plasma trap set,

wherein a first plasma trap among at least one of said upstream plasma trap set and said downstream plasma trap set includes a first plurality of corrugated peaks protruding, in a first direction parallel to said plasma tube assembly, outward from an outer surface of said first plasma trap thereby forming said outer surface of said first plasma trap, and

a second plasma trap among at least one of said upstream plasma trap set and said downstream plasma trap set includes a second plurality of corrugated peaks protruding, in a second direction parallel to said plasma tube assembly, outward from an outer surface of said second plasma trap thereby forming said outer surface of said second plasma trap, said second plurality of corrugated peaks being aligned with said first plurality of corrugated peaks, said outer surface of said first plasma trap facing said outer surface of said second plasma trap,

said first plasma trap further including a third plurality of corrugated peaks protruding, in said second direction parallel to said plasma tube assembly and said first plurality of corrugated peaks, outward from said outer surface of said first plasma trap thereby forming said outer surface of said first plasma trap, and

said second plasma trap further including a fourth plurality of corrugated peaks protruding, in said first direction parallel to said plasma tube assembly and said second plurality of corrugated peaks, outward from said outer surface of said second plasma trap thereby forming said outer surface of said second plasma trap.

23. The plasma system of claim 22 further comprising a downstream cooling manifold disposed such that substantially no air gap exists between an upstream-facing surface of said downstream cooling manifold and a downstream-facing surface of said downstream plasma trap set.

24. The plasma system of claim 22 wherein said first plurality of corrugated peaks includes at least a first corrugated peak and a second corrugated peak, said first corrugated peak surrounding said plasma tube assembly, said second corrugated peak surrounding said first corrugated peak.

25. The plasma system of claim 22 wherein said downstream plasma trap set includes at least a downstream outer plasma trap and a downstream inner plasma trap, said downstream outer plasma trap being disposed downstream relative to said downstream inner plasma trap, wherein said downstream outer plasma trap is formed of a first hollow center electrically conductive disk surrounding a passage within said plasma tube assembly, and wherein a second hollow center electrically conductive disk is disposed upstream of said first hollow center electrically conductive disk, said second hollow center electrically conductive disk also surrounding said passage within said plasma tube assembly, and a first interstitial region is disposed between said first hollow center electrically conductive disc and said second hollow center electrically conductive disc.

26. The plasma system of claim 25 wherein said first interstitial region forms an air gap.

27. The plasma system of claim 25 wherein said first interstitial region is formed of a solid material other than air.

28. The plasma system of claim 25 wherein said downstream inner plasma trap is formed of said second hollow center electrically conductive disk, wherein a third hollow center electrically conductive disk is disposed upstream relative to said second hollow center electrically conductive disk, and a second interstitial region is disposed between said second hollow center electrically conductive disc and said third hollow center electrically conductive disc.

29. The plasma system of claim 28 wherein said second interstitial region forms an air gap.

30. The plasma system of claim 28 wherein said second interstitial region is formed of a solid material other than air.

31. The plasma system of claim 22 wherein said microwave guide assembly includes a sliding short configured for tuning said microwave guide assembly.

32. The plasma system of claim 22 wherein a downstream outer plasma trap among said downstream plasma trap set is formed of a first solid center electrically conductive disk surrounding a passage within said plasma tube assembly, wherein a second solid center electrically conductive disk is disposed upstream of said first solid center electrically conductive disk, said second solid center electrically conductive disk also surrounding said passage within said plasma tube assembly, and a first interstitial region is disposed between said first solid center electrically conductive disc and said second solid center electrically conductive disc.

33. The plasma system of claim 32 wherein said first interstitial region forms an air gap.

34. The plasma system of claim 32 wherein said first interstitial region is formed of a solid material other than air.

35. The plasma system of claim 32 wherein said downstream inner plasma trap is formed of said second solid center electrically conductive disk, wherein a third solid center electrically conductive disk is disposed upstream relative to said second solid center electrically conductive disk, and a second interstitial region is disposed between said second solid center electrically conductive disc and said third solid center electrically conductive disc.

36. The plasma system of claim 35 wherein said second interstitial region forms an air gap.

37. The plasma system of claim 35 wherein said second interstitial region is formed of a solid material other than air.

38. A plasma system comprising:

a microwave waveguide assembly; and

a plasma tube assembly intersecting said microwave waveguide assembly, said plasma tube assembly having a plasma-sustaining region defined by an upstream plurality of plasma traps and a downstream plurality of plasma traps,

wherein a first plasma trap among at least one of said upstream plurality of plasma traps and said downstream plurality of plasma traps includes a first plurality of corrugated peaks protruding, in a first direction parallel to said plasma tube assembly, outward from an outer surface of said first plasma trap thereby forming said outer surface of said first plasma trap,

a second plasma trap among at least one of said upstream plurality of plasma traps and downstream plurality of plasma traps includes a second plurality of corrugated peaks protruding, in a second direction parallel to said plasma tube assembly, outward from an outer surface of said second plasma trap thereby forming said outer surface of said second plasma trap, said second plurality of corrugated peaks being offset relative to said first plurality of corrugated peaks, said outer surface of said first plasma trap facing said outer surface of said second plasma trap,

said first plasma trap further including a third plurality of corrugated peaks protruding, in said second direction parallel to said plasma tube assembly and said first plurality of corrugated peaks, outward from said outer surface of said first plasma trap thereby forming said outer surface of said first plasma trap, and

said second plasma trap further including a fourth plurality of corrugated peaks protruding, in said first direction parallel to said plasma tube assembly and said second plurality of corrugated peaks, outward from said outer surface of said second plasma trap thereby forming said outer surface of said second plasma trap.

39. The plasma system of claim 38 further comprising a downstream cooling manifold disposed such that substantially no air gap exists between an upstream-facing surface of said downstream cooling manifold and a downstream-facing surface of a downstream outer plasma trap among said downstream plurality of plasma traps.

40. The plasma system of claim 38 wherein said first plurality of corrugated peaks includes at least a first corrugated peak and a second corrugated peak, said first corrugated peak surrounding said plasma tube assembly, said second corrugated peak surrounding said first corrugated peak.

41. The plasma system of claim 38 wherein a downstream outer plasma trap among said downstream plurality of plasma traps is formed of a first hollow center electrically conductive disk surrounding a passage within said plasma tube assembly, wherein a second hollow center electrically conductive disk is disposed upstream of said first hollow center electrically conductive disk, said second hollow center electrically conductive disk also surrounding said passage within said plasma tube assembly, and a first interstitial region is disposed between said first hollow center electrically conductive disc and said second hollow center electrically conductive disc.

42. The plasma system of claim 41 wherein said first interstitial region forms a first air gap.

43. The plasma system of claim 41 wherein said first interstitial region forms a first solid structure.

44. The plasma system of claim 41 wherein a downstream inner plasma trap among said downstream plurality of plasma traps is formed of said second hollow center electrically conductive disk, wherein a third hollow center electrically conductive disk is disposed upstream relative to said second hollow center electrically conductive disk, and a second interstitial region is disposed between said second hollow center electrically conductive disc and said third hollow center electrically conductive disc.

45. The plasma system of claim 44 wherein said second interstitial region forms a second air gap.

46. The plasma system of claim 44 wherein said second interstitial region forms a second solid structure.

47. The plasma system of claim 38 wherein a downstream outer plasma trap among said downstream plurality of plasma traps is formed of a first solid center electrically conductive disk surrounding a passage within said plasma tube assembly, wherein a second solid center electrically conductive disk is disposed upstream of said first solid center electrically conductive disk, said second solid center electrically conductive disk also surrounding said passage within said plasma tube assembly, and a first interstitial region is disposed between said first solid center electrically conductive disc and said second solid center electrically conductive disc.

48. The plasma system of claim 47 wherein said first interstitial region forms a first air gap.

49. The plasma system of claim 47 wherein said first interstitial region forms a first solid structure.

50. The plasma system of claim 47 wherein a downstream inner plasma trap among said downstream plurality of plasma traps is formed of said second solid center electrically conductive disk, wherein a third solid center electrically conductive disk is disposed upstream relative to said second solid center electrically conductive disk, and a second interstitial region is disposed between said second solid center electrically conductive disc and said third solid center electrically conductive disc.

51. The plasma system of claim 50 wherein said second interstitial region forms a second air gap.

52. The plasma system of claim 50 wherein said second interstitial region forms a second solid structure.