Process apparatus and method for improving plasma production of an inductively coupled plasma

• US 20040060517A1
• Filed: 09/26/2002
• Published: 04/01/2004
• Est. Priority Date: 09/26/2002
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited TBS Broadcast Center
• Inventors: Vukovic, Mirko, Sill, Edward L.
• Granted Patent: US 7,255,774 B2
• Time in Patent Office: Days
• US Class Current: 118/723I
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma

Abstract

A processing system for processing a substrate with a plasma comprises a processing chamber defining a processing space for containing a substrate to be processed with a plasma formed within the chamber. A dielectric window interfaces with the processing chamber proximate the processing space. A core element formed of a material having a high magnetic permeability is positioned outside of the chamber proximate the dielectric window, and an electrically conductive element surrounds a portion of the core element of high magnetic permeability. The conductive element, when electrical current is conducted thereby, is operable for coupling a magnetic flux into the chamber through the dielectric window for affecting a plasma in the processing space. The core element is configured for directing a portion of the magnetic flux in a direction toward the dielectric window to efficiently couple the channeled flux into the processing chamber through the dielectric window.

Claims

1. A processing system for processing a substrate with a plasma, comprising:

a processing chamber defining a processing space for containing a substrate to be processed with a plasma formed within the processing chamber;

a dielectric window interfacing with the processing chamber proximate the processing space;

a core element formed of a material having a high magnetic permeability, the core element positioned outside of the processing chamber proximate the dielectric window; and

an electrically conductive element wound around a portion of the core element of high magnetic permeability, the electrically conductive element, when electrical current is conducted thereby, operative to generate a magnetic flux, a first portion of the magnetic flux directed into the processing space through the dielectric window for coupling with the plasma in the processing space;

the core element directing a second portion of the magnetic flux toward the dielectric window to efficiently couple the magnetic flux into the processing chamber through the dielectric window.

2. The processing system of claim 1 wherein said electrically conductive element is a conductive coil wound around a portion of the core element.

3. The processing system of claim 1 wherein at least a portion of the electrically conductive element is embedded in the core element.

4. The processing system of claim 3 further comprising a channel formed in a surface of the core element, at least a portion of the electrically conductive element being embedded in the core element by being positioned in the channel.

5. The processing system of claim 1 wherein said core element comprises a generally planar portion oriented generally parallel to the dielectric window and a post portion disposed generally perpendicular to said dielectric window, the post portion directing the second portion of the magnetic flux toward the dielectric window.

6. The processing system of claim 5 further comprising an annular portion disposed generally perpendicular to said dielectric window and radially spaced from the post portion for further directing the second portion of the magnetic flux toward the dielectric window.

7. The processing system of claim 5 wherein said electrically conductive element is a conductive coil wound helically around the post portion of the core element to be generally coaxial with the post portion.

8. The processing system of claim 7 further comprising a generally hollow opening extending through the post portion and part of the planar portion, the conductive coil surrounding part of the hollow opening.

9. The processing system of claim 1 wherein said core element comprises a generally planar portion oriented generally parallel to the dielectric window.

10. The processing system of claim 9 wherein said electrically conductive element is a conductive coil wound around the planar portion of the core element.

11. The processing system of claim 10 wherein said coil has one of a spiral shape and a concentric circular shape.

12. The processing chamber of claim 1 wherein the core element is operative for directing the second portion of the magnetic flux in a direction generally perpendicular to a plane containing the dielectric window.

13. The processing chamber of claim 1 wherein said material having a high magnetic permeability is formed from a powder of a material selected from the group consisting of iron, iron-nickel alloys, iron-molybdenum alloys, and iron-nickel-molybdenum alloys, said powder including particles covered by an electrically insulating outer layer.

14. The processing chamber of claim 1 wherein said material having a high magnetic permeability is a mixture of an iron oxide and a metal oxide.

15. The processing chamber of claim 14 wherein said metal oxide is selected from the group consisting of manganese oxide, zinc oxide, nickel oxide, and magnesium oxide.

16. The processing chamber of claim 14 wherein said mixture further includes a metal carbonate.

17. The processing chamber of claim 16 wherein said metal carbonate is selected from the group consisting of manganese carbonate, zinc carbonate, nickel carbonate, and magnesium carbonate.

18. The processing chamber of claim 1 wherein said material having a high magnetic permeability is a mixture of iron oxide and a metal carbonate.

19. The processing chamber of claim 18 wherein said metal carbonate is selected from the group consisting of manganese carbonate, zinc carbonate, nickel carbonate, and magnesium carbonate.

20. The processing chamber of claim 1 wherein said material having a high magnetic permeability has a relative magnetic permeability in the range of about 50 to about 100.

21. A processing system for processing a substrate with a plasma, comprising:

a processing chamber defining a processing space for containing a substrate to be processed with a plasma formed within the chamber;

a dielectric window interfacing with the processing chamber proximate the processing space, the dielectric window including a generally planar end wall portion and a generally planar side wall portion depending at an angle to the end wall portion;

a core element formed of a material having a high magnetic permeability, the core element positioned outside of the processing chamber proximate the dielectric window; and

an electrically conductive element wound around a portion of the core element of high magnetic permeability, the electrically conductive element, when electrical current is conducted thereby, operative to generate a magnetic flux, a first portion of the magnetic flux directed into the processing chamber through the dielectric window for coupling with the plasma in the processing space;

the core element operative to direct a second portion of the magnetic flux toward the planar end wall portion of the dielectric window and a third portion of the magnetic flux toward the planar side wall portion of the dielectric window to efficiently couple the magnetic flux into the processing chamber through the dielectric window.

22. The processing system of claim 21 wherein said electrically conductive element is a conductive coil wound around a portion of the core element.

23. The processing system of claim 21 wherein at least a portion of the electrically conductive element is embedded in the core element.

24. The processing system of claim 23 further comprising a channel formed in a surface of the core element, at least a portion of the electrically conductive element being embedded in the core element by being positioned in the channel.

25. The processing system of claim 21 wherein said core element comprises a generally planar portion oriented generally parallel to the dielectric window end wall portion and a post portion disposed generally perpendicular to said dielectric window end wall portion, the post portion directing the first portion of the magnetic flux toward the end wall portion of the dielectric window.

26. The processing system of claim 25 wherein said core element further comprises an annular portion disposed generally parallel to the side wall portion of the dielectric window and radially outwardly from the side wall portion for directing the second portion of the magnetic flux toward the side wall portion of the dielectric window.

27. The processing system of claim 25 wherein said electrically conductive element is a conductive coil wound around the post portion of the core element to be generally coaxial with the post portion.

28. The processing system of claim 27 further comprising a generally hollow opening extending through the post portion and part of the planar portion, the conductive coil surrounding part of the hollow opening.

29. The processing system of claim 21 wherein said core element comprises a generally planar portion oriented generally parallel to the dielectric window planar portion and a side wall portion disposed generally parallel to the side wall portion of the dielectric window, the side wall portion further directing the second portion of the magnetic flux toward the dielectric window side wall portion.

30. The processing system of claim 29 wherein said electrically conductive element is a conductive coil wound around the side wall portion of the core element to be generally coaxial with the side wall portion.

31. The processing chamber of claim 21 wherein said material having a high magnetic permeability is formed from a powder of a material selected from the group consisting of iron, iron-nickel alloys, iron-molybdenum alloys, and iron-nickel-molybdenum alloys, said powder including particles covered by an electrically insulating outer layer.

32. The processing chamber of claim 21 wherein said material having a high magnetic permeability is a mixture of an iron oxide and a metal oxide.

33. The processing chamber of claim 32 wherein said metal oxide is selected from the group consisting of manganese oxide, zinc oxide, nickel oxide, and magnesium oxide.

34. The processing chamber of claim 32 wherein said mixture further includes a metal carbonate.

35. The processing chamber of claim 34 wherein said metal carbonate is selected from the group consisting of manganese carbonate, zinc carbonate, nickel carbonate, and magnesium carbonate.

36. The processing chamber of claim 21 wherein said material having a high magnetic permeability is a mixture of iron oxide and a metal carbonate.

37. The processing chamber of claim 36 wherein said metal carbonate is selected from the group consisting of manganese carbonate, zinc carbonate, nickel carbonate, and magnesium carbonate.

38. The processing chamber of claim 21 wherein said material having a high magnetic permeability has a relative magnetic permeability in the range of about 50 to about 100.

39. The processing chamber of claim 21 wherein the core element is operative for directing the second portion of the magnetic flux in a direction generally perpendicular to a plane containing the dielectric window.

40. A processing system for processing a substrate with a plasma, comprising:

a processing chamber defining a processing space for containing a substrate to be processed with a plasma formed within the processing chamber;

a dielectric window interfacing with the processing chamber proximate the processing space;

an electrically conductive element positioned proximate to said dielectric window, the electrically conductive element, when electrical current is conducted thereby, operative to generate a magnetic flux, a first portion of the magnetic flux directed into the chamber through the dielectric window for generating the plasma in the processing space; and

means for channeling a second portion of the magnetic flux toward the dielectric window to efficiently couple the channeled flux into the processing chamber through the dielectric window.

41. The processing system of claim 40 wherein the directing means includes a core element formed of a material having a high magnetic permeability, the core element being positioned outside of the processing chamber proximate the dielectric window, and the electrically conductive element being wound about a portion of the core element.

42. The processing chamber of claim 40 wherein said material having a high magnetic permeability has a relative,magnetic permeability in the range of about 50 to about 100.

43. A method for processing a substrate with a plasma, comprising:

placing a substrate in a processing space of a processing chamber;

evacuating the processing space to a vacuum pressure;

providing a process gas to said processing space;

generating a magnetic flux;

directing a first portion of the magnetic flux through a dielectric window into the processing space to couple with a plasma generated from the process gas; and

directing a second portion of the magnetic flux toward the dielectric window with a core element formed of a material having a high magnetic permeability.

44. The method of claim 43 wherein the step of directing includes orienting field lines of the second portion of the magnetic flux in a direction generally perpendicular to a plane containing the dielectric window