Claims
- 1. A coil for a plasma processor, the coil comprising first and second excitation terminals for connection to opposite first and second terminals of RF excitation circuitry, at least one winding connected to said first and second excitation terminals, and a shorting turn coupled to the at least one winding.
- 2. The coil of claim 1 wherein the at least one winding extends in generally radial and circumferential directions between inner and peripheral portions of the coil, and the turn is coupled to the innermost portion of the coil.
- 3. The coil of claim 1 wherein the at least one winding extends in generally radial and circumferential directions between inner and peripheral portions of the coil, and the turn is coupled to the outermost portion of the coil.
- 4. The coil of claim 1 wherein the at least one winding extends in generally radial and circumferential directions between inner and peripheral portions of the coil, and the turn is coupled to an intermediate portion of the coil between interior and exterior portions of the coil.
- 5. The coil of claim 1 wherein the at least one winding extends in generally radial and circumferential directions between inner and peripheral portions of the coil, and the first and second excitation terminals are respectively at the interior and exterior portions of the coil.
- 6. The coil of claim 5 wherein the coil includes plural multi-turn windings connected in parallel to said first and second excitation terminals.
- 7. The coil of claim 6 wherein said multi-turn windings are interleaved spirals.
- 8. The coil of claim 7 wherein the RF impedance of the shorting turn for the RF derived by the RF excitation circuitry is such that the RF voltage is substantially the same at corresponding angles of each of said windings.
- 9. The coil of claim 1 wherein the shorting turn is ohmically connected to the at least one winding.
- 10. The coil of claim 1 wherein the coil includes plural multi-turn windings connected in parallel to said excitation terminals, and each of the windings extends in generally radial and circumferential directions between inner and peripheral portions of the coil and the shorting turn is ohmically connected to similar spatial segments of each of said windings.
- 11. The coil of claim 1 wherein the shorting turn is only reactively coupled with other parts of the coil.
- 12. The coil of claim 1 in combination with a plasma processor including the RF excitation circuitry and a vacuum chamber arranged for processing a workpiece with plasma, the vacuum chamber having a window, the coil being mounted outside the chamber in proximity to the window for coupling magnetic fields through the window to the chamber interior, the RF excitation circuitry having opposite first and second terminals connected to said first and second excitation terminals.
- 13. The combination of claim 12 wherein the RF excitation circuitry includes a matching circuit and a capacitor, the matching circuit having an ungrounded terminal forming the first terminal of the RF excitation circuitry and connected to said first excitation terminal, the capacitor having a first electrode connected to said second excitation terminal and a second electrode connected to the second terminal of the RF excitation circuitry.
- 14. The combination of claim 13 wherein the RF excitation circuitry includes an RF source having first and second output terminals connected to an input terminal of the matching circuit and a grounded output terminal forming the second terminal of the RF excitation circuitry, the RF source having a frequency and each of the windings having a length such that the RF voltage and current along the length of each of the windings between the first and second excitation terminals vary in a substantially linear manner.
- 15. The combination of claim 14 wherein the length of each of the windings between the first and second excitation terminals is no longer than about ⅛ of a wavelength of the RF source frequency.
- 16. The combination of claim 13 wherein the capacitor has a value such that the RF voltages of the first and second excitation terminals are substantially the same.
- 17. The combination of claim 13 further including a sensor arrangement and a controller for the value of the capacitor.
- 18. The combination of claim 13 wherein the controller is arranged to respond to the sensor arrangement for maintaining the RF voltage magnitudes of the first and second excitation terminals substantially the same.
- 19. The combination of claim 12 wherein the RF circuitry includes an RF source, the RF source having a frequency and each of the windings having a length such that the RF voltage and current along the length of each of the other windings between the first and second excitation terminals vary in a substantially linear manner.
- 20. The combination of claim 19 wherein the length of each of the windings between the first and second excitation terminals is no longer than about ⅛ of a wavelength of the RF source frequency.
- 21. The coil of claim 1 wherein the coil includes plural multi-turn windings connected in parallel to said excitation terminals, each of said windings extending in generally radial and circumferential directions between inner and outer portions of the coil, the coil having a center and the windings being substantially co-planar, each of the windings having an innermost portion spaced by about the same distance from the coil center and an outermost portion spaced by about the same distance from the coil center.
- 22. The coil of claim 21 wherein the shorting turn: (a) is coupled to the innermost portion of each of the windings, and (b) surrounds the coil center.
- 23. The coil of claim 22 wherein the shorting turn is formed as a ring having a center substantially coincident with the center of the coil.
- 24. The coil of claim 23 wherein the windings are substantially symmetrical with respect to the center of the coil.
- 25. The coil of claim 22 wherein the shorting turn is substantially coplanar with the windings.
- 26. The coil of claim 21 wherein the shorting turn: (a) is coupled to an intermediate portion of each of the windings, and (b) surrounds the coil center.
- 27. The coil of claim 26 wherein the turn is formed as a ring having a center substantially coincident with the center of the coil.
- 28. The coil of claim 27 wherein the windings are substantially symmetrical with respect to the center of the coil.
- 29. The coil of claim 26 wherein the coil is adapted to be mounted outside of a processor chamber at a position in proximity to a window for coupling magnetic fields from the coil to the chamber and the shorting turn is interposed between the windings and the window when the coil is mounted in proximity to the window.
- 30. The coil of claim 21 wherein the shorting turn: (a) is coupled to the outermost portion of each of the windings, and (b) surrounds the coil center.
- 31. The coil of claim 30 wherein the shorting turn is formed as a ring having a center substantially coincident with the center of the coil.
- 32. The coil of claim 31 wherein the windings are substantially symmetrical with respect to the center of the coil.
- 33. The coil of claim 7 wherein the spacing between adjacent turns of each of the windings differs.
- 34. The coil of claim 33 wherein the spacing between adjacent turns of the portions of the windings in a peripheral portion of the coil differs from the spacing between adjacent turns of the portions of the windings in an inner portion of the coil.
- 35. The coil of claim 34 wherein the spacing is less in the peripheral portion than in the inner portion.
- 36. The coil of claim 34 wherein the spacing is greater in the peripheral portion than in the inner portion.
- 37. The coil of claim 6 further including a separate circuit element having opposite ends coupled to different points on the windings, the separate circuit element (a) being of a type, (b) having a value and (c) having connections for causing current flowing in different portions of the same winding to differ.
- 38. The coil of claim 37 wherein each of the circuit elements comprises a capacitor ohmically connected between corresponding equal potential points on the windings.
- 39. The coil of claim 1 wherein the shorting turn is substantially coplanar with the at least one winding.
- 40. The coil of claim 1 wherein the shorting turn is not co-planar with the at least one winding.
- 41. A coil for a plasma processor, the coil comprising first and second excitation terminals for connection to opposite first and second terminals of RF excitation circuitry, a plurality of multi-turn windings connected in parallel to said first and second excitation terminals, each of said windings extending in generally radial and circumferential directions between inner and peripheral portions of the coil, and a circuit element coupled to at least some of the multi-turn windings for decoupling fields originating in a segment of the coil from a region in the immediate vicinity of or within the coil.
- 42. The coil of claim 41 wherein the region in the immediate vicinity of the coil is inside the innermost portion of the coil.
- 43. The claim of coil 41 wherein the region in the immediate vicinity of the coil is outside the outermost portion of the coil.
- 44. The coil of claim 41 wherein the region is within the coil, between the inner and peripheral portions of the coil.
- 45. The coil of claim 41 wherein the circuit element comprises a shorting turn.
- 46. The coil of claim 45 wherein the RF impedance of the shorting turn for the RF derived by the RF excitation circuitry is such that the RF voltage is the same at each of the similar segments.
- 47. The coil of claim 41 wherein the circuit element is ohmically connected to similar spatial segments of at least some of the multi-turn windings.
- 48. The coil of claim 41 wherein the circuit element is only reactively coupled with other parts of the coil.
- 49. A coil for a plasma processor, the coil comprising first and second excitation terminals for connection to opposite first and second terminals of RF excitation circuitry, a plurality of multi-turn windings connected in parallel between said first and second excitation terminals, each of said windings extending in generally radial and circumferential directions between inner and peripheral portions of the coil, the spacing between adjacent turns of the portions of the windings at a peripheral region of the coil being less than the spacing between adjacent turns of the portions of the windings at an inner region of the coil.
- 50. The coil of claim 49 further including a shorting turn coupled to a similar spatial segment of each of the windings.
- 51. The coil of claim 49 wherein the first and second excitation terminals are respectively at the interior and exterior portions of the coil.
- 52. The coil of claim 51 wherein each of said multi-turn windings includes an Archimedes spiral configuration.
- 53. The coil of claim 52 wherein said multi-turn windings are interleaved with each other.
- 54. The coil of claim 53 wherein each of said multi-turn windings includes first and second abutting Archimedes spiral configurations having different pitches.
- 55. The coil of claim 49 wherein each of said multi-turn windings includes first and second abutting Archimedes spiral configurations having different pitches.
- 56. The coil of claim 49 in combination with a plasma processor including the RF excitation circuitry and a vacuum chamber arranged for processing a workpiece with plasma, the vacuum chamber having a window, the coil being mounted outside the chamber in proximity to the window for coupling magnetic and electric fields through the window to the chamber interior, the RF excitation circuitry opposite first and second terminals being connected to said first and second excitation terminals.
- 57. A coil for a plasma processor, the coil comprising first and second excitation terminals for connection to opposite first and second terminals of RF excitation circuitry, a plurality of multi-turn windings connected in parallel between said first and second excitation terminals, each of said windings extending in generally radial and circumferential directions between inner and peripheral portions of the coil, and a separate circuit element having opposite ends respectively coupled to first and second points on the windings, the separate circuit element (a) being of a type, (b) having a value, and (c) having connections for causing current flowing in different portions of the same winding to differ.
- 58. The coil of claim 57 further including a shorting turn coupled to the windings.
- 59. The coil of claim 57 wherein the circuit element coupled to each winding comprises an impedance element associated with only one of each of the windings, each impedance element having opposite first and second terminals respectively ohmically connected to the first and second points of the winding with which it is associated.
- 60. The coil of claim 57 wherein the plurality equals K and the number of circuit elements equals K, each circuit element having opposite first and second terminals, the first terminal of each of the circuit elements being ohmically connected to said first points on the windings having the same first RF potentials, the second terminal of each of the circuit elements being ohmically connected to second points on the windings having the same second RF potentials.
- 61. The coil of claim 60 wherein each circuit element is associated with only one of the windings, the first and second terminals of each circuit element being respectively ohmically connected to the first and second points of the winding with which it is associated.
- 62. The coil of claim 57 wherein each of said multi-turn windings has a spiral like configuration, said multi-turn windings being interleaved with each other.
- 63. The coil of claim 57 in combination with a plasma processor including the RF excitation circuitry and a vacuum chamber arranged for processing a workpiece with plasma, the vacuum chamber having a window, the coil being mounted outside the chamber in proximity to the window for coupling magnetic and electric fields through the window to the chamber interior, the RF excitation circuitry opposite first and second terminals being connected to said first and second excitation terminals.
- 64. A coil for a plasma processor, the coil comprising first and second excitation terminals for connection to opposite first and second terminals of RF excitation circuitry, a plurality of multi-turn Archimedes spiral windings connected in parallel to said first and second excitation terminals, the turns of each of said windings extending arcuately in generally radial and circumferential directions between inner and peripheral portions of the coil, at least one of said windings having a plurality of pitches.
- 65. The coil of claim 64 wherein the pitch in an interior portion of the coil exceeds the pitch in an outer portion of the coil.
- 66. The coil of claim 64 wherein the pitch in an exterior portion of the coil exceeds the pitch in an inner portion of the coil.
- 67. The coil of claim 64 wherein each of said windings has a plurality of pitches.
- 68. The coil of claim 67 wherein the first and second excitation terminals are respectively at the interior and exterior portions of the coil.
- 69. The coil of claim 64 wherein said multi-turn windings are interleaved.
- 70. The coil of claim 69 where each of said windings includes a plurality of abutting portions having different pitches, substantial segments of the portions being Archimedes spirals.
- 71. The coil of claim 70 wherein each of the windings has substantially the same configuration.
- 72. The coil of claim 71 wherein the windings are symmetrical with respect to a center point of the coil.
- 73. The coil of claim 72 wherein first and second of said segments of each winding are respectively substantially represented in polar coordinates by R=k1θ for θ from θ1 to an angle somewhat less than θ2 and R=k2θ for θ somewhat greater than θ2 to θ=θ3, where R is the radial distance of each winding from the center of the coil, θ is the angle around the winding in radians, k1≠k2, and R between the angle somewhat less than θ2 to the angle somewhat greater than θ2 is such that the slopes of the first and second portions at θ2 are the same.
- 74. The coil of claim 73 where k1 is less than k2 for values of less than θ2.
- 75. The coil of claim 73 where k1 is greater than k2 for values of less than θ2.
- 76. A coil for a plasma processor, the coil comprising first and second excitation terminals for connection to opposite first and second terminals of RF excitation circuitry, at least one multi-turn Archimedes spiral winding connected to said first and second terminals, the turns of the at least one winding extending arcuately in generally radial and circumferential directions between inner and peripheral portions of the coil, the at least one winding having plural pitches.
- 77. The coil of claim 76 wherein first and second of said segments of said at least one winding are respectively substantially represented in polar coordinates by R=k1θ for θ from θ1 to an angle somewhat less than θ2 and R=k2θ for θ somewhat greater than θ2 to θ=θ3, where R is the radial distance of said at least one winding from the center of the coil, θ is the angle around the winding in radians, k1≠k2, and R between the angle somewhat less than θ2 to the angle somewhat greater than θ2 is such that the slopes of the first and second portions at θ2 are the same.
- 78. The coil of claim 77 where k1 is less than k2 for values of less than θ2.
- 79. The coil of claim 77 where k1 is greater than k2 for values of less than θ2.
RELATION TO CO-PENDING APPLICATION
[0001] The present application is a continuation-in-part of the co-pending, commonly assigned provisional application Serial No. 60/322,581, filed Sep. 14, 2001, entitled Galaxy TCP Coil.
Provisional Applications (1)
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Number |
Date |
Country |
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60322581 |
Sep 2001 |
US |