Methods and arrangement for the reduction of byproduct deposition in a plasma processing system

• US 7,959,984 B2
• Filed: 12/22/2004
• Issued: 06/14/2011
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Lohokare, Shrikant P., Bailey, Andrew D. III
• Primary Examiner(s): Meeks; Timothy H
• Assistant Examiner(s): Burkhart; Elizabeth
• Application Number:
  US11/022,982
• Publication Number:
  US 20060130758A1
• Time in Patent Office: 2,365 Days
• Field of Search: 427/569, 174/350, 204/192.1, 118/504, 118/723.R
• US Class Current: 427/569
• CPC Class Codes: C23C 16/4404 Coatings or surface treatment on the inside of the reaction chamber or on parts thereof
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01J 37/32633 Baffles

Abstract

In a plasma processing system, a method of reducing byproduct deposits on a set of plasma chamber surfaces of a plasma processing chamber is disclosed. The method includes providing a deposition barrier in the plasma processing chamber, the deposition barrier is configured to be disposed in a plasma generating region of the plasma processing chamber, thereby permitting at least some process byproducts produced when a plasma is struck within the plasma processing chamber to adhere to the deposition barrier and reducing the byproduct deposits on the set of plasma processing chamber surfaces.

Claims

1. A method for reducing byproduct deposits on a set of plasma chamber surfaces of a plasma processing chamber in a plasma processing system for processing at least a substrate, said byproduct deposits being produced from said substrate, the method comprising:

providing a deposition barrier in said plasma processing chamber, said deposition barrier is configured to be disposed in a plasma generating region of said plasma processing chamber, thereby permitting at least some process byproducts produced when a plasma is struck within said plasma processing chamber to adhere to said deposition barrier and reducing said byproduct deposits on said set of plasma processing chamber surfaces;

providing a structure inside said plasma processing chamber and under said deposition barrier;

supporting said deposition barrier using said structure, said structure being attached to a bottom of said plasma processing chamber, said structure enabling said deposition barrier to be repositioned relative to said bottom of said plasma processing chamber;

positioning said deposition barrier at a first position inside said plasma processing chamber relative to said bottom of said plasma processing chamber;

striking a first plasma in said plasma processing chamber when said deposition barrier is at said first position;

using said deposition barrier to contact a first subset of said byproduct deposits when said deposit barrier is at said first position;

re-positioning said deposition barrier to a second position inside said plasma processing chamber relative to said bottom of said plasma processing chamber;

striking a second plasma in said plasma processing chamber when said deposition barrier is at said second position;

using said deposition barrier to contact a second subset of said byproduct deposits when said deposition barrier is at said second position; and

including a resistant material in said deposition barrier, said resistant material being resistant to attack of said plasma.

2. The method of claim 1 wherein said deposition barrier is a Faraday shield.

3. The method of claim 1 further comprising:

cooling said deposition barrier; and

after said cooling, cleaning said deposition barrier in-situ using a plasma cleaning process.

4. The method of claim 1 wherein said deposition barrier is coated by said resistant material.

5. The method of claim 1 , wherein said deposition barrier comprises at least one of polytetrafluoroethylene, BN, BC, SiN, SiO, SiC, and plastic.

6. The method of claim 1 further comprising:

lowering said deposition barrier onto a chuck for protecting said chuck, said chuck being disposed inside said plasma processing chamber for supporting said substrate during processing of said substrate; and

after said lowering, cleaning said plasma processing chamber when said chuck is protected by said deposition barrier.

7. The method of claim 1, further comprising independently heating said deposition barrier irrespective of said first plasma and said second plasma.

8. The method of claim 1, further comprising applying a RF bias to said deposition barrier.

9. The method of claim 1 wherein said deposition barrier comprises a metal that does not generate a substantial quantity of volatile etch byproducts when exposed to said plasma.

10. The method of claim 9 further comprising simultaneously removing both said substrate and said deposition barrier from said plasma processing chamber.

11. The method of claim 1 further comprising;

heating said deposition barrier; and

after said heating, cleaning said deposition barrier in-situ using a plasma cleaning process.

12. The method of claim 1 further comprising performing ex-situ cleaning of said deposition barrier using a wet chemical flush process.

13. The method of claim 12, wherein said deposition barrier comprises a material that is substantially resistant to a wet clean process.

14. The method of claim 12, wherein said deposition barrier is coated by a material that is substantially resistant to a wet clean process.

15. The method of claim 1, wherein said deposition barrier can be removed while substantially maintaining a vacuum in the plasma chamber.

16. The method of claim 15, wherein said removal can be accomplished by a vacuum robot under automatic control.

17. The method of claim 1, wherein said deposition barrier can be replaced in-situ.

18. The method of claim 1, wherein said deposition barrier includes a substantially continuous surface.

19. The method of claim 1, wherein said deposition barrier includes a set of holes.

20. The method of claim 1, further comprising removing said deposition barrier prior to removing said substrate from said plasma processing chamber.

21. The method of claim 1, further comprising removing said deposition barrier after removing said substrate from said plasma processing chamber.

22. The method of claim 1, further comprising:

performing a first substrate processing cycle using said plasma processing chamber; and

after said performing said first substrate processing cycle and before performing a second substrate processing cycle using said plasma processing chamber, lowering said deposition barrier onto a chuck for protecting said chuck, said chuck being disposed inside said plasma processing chamber for supporting said substrate.

23. The method of claim 1, further comprising including a material in said deposition barrier for generating a set of volatile etch products, said set of volatile etch products being generated when said deposition barrier is exposed to said plasma.

24. The method of claim 1, wherein said deposition barrier protects a source RF.

25. The method of claim 24 wherein said source RF comprises an inductive source.

26. The method of claim 25 wherein said source RF is configured to protect a dielectric coupling window for said inductive source.

27. The method of claim 24 wherein said source RF comprises a capacitive source.

28. The method of claim 24 wherein said source RF comprises an inductive source and a capacitive source.

29. The method of claim 24 wherein said source RF comprises ECR source.

30. The method of claim 24 wherein said source RF comprises a microwave source.

31. The method of claim 1, wherein said plasma processing system includes a source RF that is coupled from a top of said plasma processing chamber.

32. The method of claim 1, wherein said plasma processing system includes a source RF that is coupled from a side of said plasma processing chamber.

33. The method of claim 1, wherein said plasma processing system includes a source RF that is coupled from a bottom of said plasma processing chamber.

34. The method of claim 1, wherein said set of plasma chamber surfaces is configured to be independently heated.

35. The method of claim 1, wherein said set of plasma chamber surfaces is configured to be independently cooled.

36. The method of claim 1 further comprising:

independently heating a set of plasma chamber walls of said plasma processing chamber irrespective of said first plasma and said second plasma.

37. The method of claim 1 further comprising independently cooling said deposition barrier irrespective of said first plasma and said second plasma.

38. The method of claim 1 further comprising:

halting processing of substrates in said plasma processing chamber at least until said deposition barrier is cooled down to a predefined temperature threshold; and

cleaning said deposition barrier in-situ after said deposition barrier is cooled at least down to said predefined temperature threshold.

39. The method of claim 1 wherein said deposition barrier is cleaned in-situ by a plasma cleaning process when said deposition barrier has heated up.

41. The method of claim 1 , wherein said deposition barrier surface has a pre-determined roughness which facilitates control of adhesion of the depositing material.

42. The method of claim 1, wherein said deposition barrier surface has a pre-determined surface composition which facilitates control of adhesion of the depositing material.

40. The method of 1 wherein said deposition barrier is configured to protect a set of gas injectors from said byproduct deposits

43. A method of reducing a set of byproduct deposits on a set of plasma chamber surfaces in a plasma reactor, the method comprising:

positioning a substrate in a plasma processing chamber;

positioning a deposition barrier in said plasma processing chamber;

providing a structure inside said plasma processing chamber and under said deposition barrier;

supporting said deposition barrier using said structure, said structure being attached to a bottom of said plasma processing chamber, structure enabling said deposition barrier to be repositioned relative to said bottom of said plasma processing chamber;

positioning said deposition barrier at a first position inside said plasma processing chamber relative to said bottom of said plasma processing chamber;

striking a first plasma in said plasma processing chamber such that said first plasma surrounds said deposition barrier when said deposition barrier is at said first position;

using said deposition barrier to contact a first subset of said set of byproduct deposits when said deposition barrier is at said first position, said byproduct deposits being produced from said substrate;

re-positioning said deposition barrier to a second position inside said plasma processing chamber relative to said bottom of said plasma processing chamber;

striking a second plasma in said plasma processing chamber when said deposition barrier is at said second position;

using said deposition barrier to contact a second subset of said set of byproduct deposits when said deposition barrier is at said second position;

cooling said deposition barrier; and

after said cooling, cleaning said deposition barrier in-situ using a plasma cleaning process.

44. A deposition barrier arrangement configured to reduce byproduct deposits on a set of plasma chamber surfaces of a plasma processing chamber, the deposition barrier arrangement comprising:

a deposition barrier disposed in a plasma generating region of said plasma processing chamber, said deposition barrier being configured to enable at least some process byproducts produced when a plasma is struck within said plasma processing chamber to adhere to said deposition barrier and thereby reducing said byproduct deposits on said set of plasma chamber surfaces;

a structure disposed inside said plasma processing chamber and disposed under said deposition barrier, said structure supporting said deposition barrier, said structure being attached to a bottom of said plasma processing chamber, said structure being configured for repositioning said deposition barrier relative to said bottom of said plasma processing chamber,

wherein said deposition barrier comprises a material for generating a set of volatile etch products when said deposition barrier is exposed to said first plasma.