Patent US5685941A successfully refreshed from Google Patents.
US5685941A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inductively coupled plasma reactor with top electrode for enhancing plasma ignition
Assignee: Applied Materials Inc
•
Filing: 1995-11-21
•
Granted: 1997-11-11
•
Expires: 2015-11-21
Abstract
Abstract A plasma reactor for carrying out plasma processing of a semiconductor substrate includes a vacuum chamber including apparatus for introducing a gas into the interior thereof, an induction coil encircling a region of the vacuum chamber, the coil being connected across an RF power source, and an electrode positioned adjacent the region and connected to the RF power source for capacitively coupling RF power to the gas in the interior of the vacuum chamber. The electrode has a surface area facing the region which is large enough to provide capacitive coupling of RF power to the gas in the region sufficient to facilitate igniting a plasma, but which is small enough so that, during steady-state maintenance of the plasma, most of the RF power coupled to the plasma from the RF power source is coupled inductively rather than capacitively.
Inventors
- 👤 John Forster
- 👤 Barney M. Cohen
- 👤 Bradley O. Stimson
- 👤 George Proulx
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:11
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32082; H01J37/32091; H01J37/321; H01J37/3211; H01J37/32431; H01J37/32532; H01J37/32568; H05; H05H; H05H1/00; H05H1/24; H05H1/46
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
169 words
A plasma reactor for carrying out plasma processing of a semiconductor substrate, comprising: a vacuum chamber including means for introducing a gas into the interior thereof; an induction coil facing a region of said vacuum chamber, said coil being connected across an RF power source and an integrated auxiliary electrode electrically connected at a portion of said induction coil with a potential sufficient to facilitate igniting a plasma; and wherein said auxiliary electrode is located adjacent said region and connected to said RF power source for capacitively coupling RF power to said gas in said vacuum chamber, said auxiliary electrode having a surface area facing said region and covering an area of said region suitable to limit capacitive coupling of RF power to said gas in said vacuum chamber to a level which is still sufficient to facilitate igniting a plasma so that, during steady-state maintenance of the plasma, most of the RF power coupled to the plasma from said RF power source is coupled inductively rather than capacitively.
Claim 2
Dependent Claim
169 words
A plasma reactor for carrying out plasma processing of a semiconductor substrate, comprising: a vacuum chamber including means for introducing a gas into the interior thereof; an induction coil facing a region of said vacuum chamber, said coil being connected across an RF power source and an integrated auxiliary electrode electrically connected at a portion of said induction coil with a potential sufficient to facilitate igniting a plasma; and wherein said auxiliary electrode is located adjacent said region and connected to said RF power source for capacitively coupling RF power to said gas in said vacuum chamber, said auxiliary electrode having a surface area facing said region and covering an area of said region suitable to limit capacitive coupling of RF power to said gas in said vacuum chamber to a level which is still sufficient to facilitate igniting a plasma so that, during steady-state maintenance of the plasma, most of the RF power coupled to the plasma from said RF power source is coupled inductively rather than capacitively.
Claim 3
Dependent Claim
42 words
The plasma reactor of claim 1 wherein a first portion of said auxiliary electrode lies between said induction coil and said vacuum chamber, said first portion having at least an aperture therein to prevent a closed conductive path around said inductive coil.
Claim 4
Dependent Claim
51 words
The plasma reactor of claim 2 wherein said coil comprises a first terminal connected to an energized terminal of said RF power source and a second terminal which is grounded, and wherein said auxiliary electrode further comprises a second portion connected to said induction coil between said first and second terminals.
Claim 5
Dependent Claim
47 words
The plasma reactor of claim 3 wherein: said second portion of said auxiliary electrode comprises a center connection region; and said first portion of said auxiliary electrode comprises plural arms separated by apertures therebetween and radiating outwardly from said center connection region and across said induction coil.
Claim 6
Dependent Claim
58 words
The plasma reactor of claim 4 wherein said center connection region is a closed circular conductive disk, said inductive coil having an opening therethrough near the center thereof, said center connection region being in registration with said opening of said induction coil so as to avoid being between said induction coil and the interior of said vacuum chamber.
Claim 7
Dependent Claim
79 words
The plasma reactor of claim 5 wherein said vacuum chamber comprises a sealed container having a circular cross-sectional shape and a top centered at an axis of symmetry of said circular cross-sectional shape, said induction coil being wound around said sealed container so that said opening of said induction coil coincides with said top of said sealed container, and wherein said center connection region of said auxiliary electrode is on said top and centered at said axis of symmetry.
Claim 8
Dependent Claim
22 words
The plasma reactor of claim 6 wherein said auxiliary electrode comprises a film deposited on an exterior surface of said sealed container.
Claim 9
Dependent Claim
35 words
The plasma reactor of claim 6 wherein said sealed container comprises a dome and wherein said top comprises an apex of said dome, and wherein arms of said auxiliary electrode extend downwardly from said apex.
Claim 10
Dependent Claim
26 words
The plasma reactor of claim 8 wherein each of said arms has a width less than 5% of the circumference of the base of said dome.
Claim 11
Dependent Claim
33 words
The plasma reactor of claim 8 wherein said induction coil is wound around a lower portion of said dome so as to leave said opening therethrough centered at said apex of said dome.
Claim 12
Dependent Claim
25 words
The plasma reactor of claim 10 wherein said induction coil is spaced from said dome to accommodate said second portion of said auxiliary electrode therebetween.
Claim 13
Dependent Claim
19 words
The plasma reactor of claim 1 further comprising a capacitor having one side thereof connected to said auxiliary electrode.
Claim 14
Dependent Claim
19 words
The plasma reactor of claim 12 wherein an opposite side of said capacitor is connected to a ground terminal.
Claim 15
Dependent Claim
36 words
The plasma reactor of claim 1 further comprising: a wafer pedestal in the interior of said vacuum chamber for supporting said semiconductor substrate thereon; and means for applying a selected electrical potential to said wafer pedestal.
Claim 16
Dependent Claim
25 words
The plasma reactor of claim 14 wherein said means for applying comprises means for applying a ground potential to said wafer pedestal during plasma ignition.
Claim 17
Dependent Claim
27 words
The plasma reactor of claim 14 wherein said means for applying comprises means for applying an RF bias power source to said wafer pedestal during plasma ignition.
Claim 18
Dependent Claim
25 words
The plasma reactor of claim 1 wherein said surface area of said auxiliary electrode is not more than 10% of that of said induction coil.
Claim 19
Dependent Claim
32 words
The plasma reactor of claim 6 wherein said vacuum chamber has a cylindrical shape and said induction coil is wound in a cylinder around at least a portion of said vacuum chamber.
Claim 20
Dependent Claim
48 words
The plasma reactor of claim 1 wherein the surface area of said auxiliary electrode covers an area suitable to limit capacitive coupling to an amount sufficient for plasma ignition at a selected pressure in said vacuum chamber at a selected RF power level of said RF power source.
Claim 21
Dependent Claim
36 words
The plasma reactor of claim 19 wherein at least one of said selected RF power level and said selected pressure is substantially less than that required for plasma ignition in an absence of said auxiliary electrode.
Claim 22
Dependent Claim
33 words
The plasma reactor of claim 19 wherein at least one of said selected RF power level and said selected pressure is not substantially greater than that employed during plasma processing of said wafer.
Claim 23
Dependent Claim
19 words
The plasma reactor of claim 21 wherein said selected pressure is in a range between 0.5 and 50 milliTorr.
Claim 24
Dependent Claim
18 words
The plasma reactor of claim 22 wherein said selected power level is on the order of 225 Watts.
Claim 25
Dependent Claim
139 words
A plasma reactor for carrying out plasma processing of a semiconductor substrate, comprising: a vacuum chamber including means for introducing a gas into the interior thereof; an induction coil surrounding a portion of said vacuum chamber, said coil being connected across an RF power source, and an integrated auxiliary electrode electrically connected at a portion of said induction coil with a potential sufficient to facilitate igniting a plasma; and wherein said RF powered auxiliary electrode has a surface area facing said interior of said vacuum chamber so as to capacitively couple RF power to the gas in said interior of said vacuum chamber said surface area of said auxiliary electrode being limited in area covering said chamber to limit capacitive coupling therefrom to said gas to an amount sufficient for plasma ignition at a selected pressure in said chamber.
Claim 26
Dependent Claim
139 words
A plasma reactor for carrying out plasma processing of a semiconductor substrate, comprising: a vacuum chamber including means for introducing a gas into the interior thereof; an induction coil surrounding a portion of said vacuum chamber, said coil being connected across an RF power source, and an integrated auxiliary electrode electrically connected at a portion of said induction coil with a potential sufficient to facilitate igniting a plasma; and wherein said RF powered auxiliary electrode has a surface area facing said interior of said vacuum chamber so as to capacitively couple RF power to the gas in said interior of said vacuum chamber said surface area of said auxiliary electrode being limited in area covering said chamber to limit capacitive coupling therefrom to said gas to an amount sufficient for plasma ignition at a selected pressure in said chamber.
Claim 27
Dependent Claim
31 words
The plasma reactor of claim 24 wherein said auxiliary electrode is limited in area in that it covers an area not more than 10% of that covered by said induction coil.
Claim 28
Dependent Claim
19 words
The plasma reactor of claim 24 wherein said selected pressure is on the order of less than 100 milliTorr.
Claim 29
Dependent Claim
25 words
The plasma reactor of claim 24 wherein said selected pressure lies in a range between on the order of approximately 0.5 milliTorr and 30 milliTorr.
Claim 30
Dependent Claim
41 words
The plasma reactor of claim 24 wherein said auxiliary electrode comprises a first portion lying between said induction coil and said vacuum chamber, said first portion having at least an aperture therethrough preventing a closed conducting path around said induction coil.
Claim 31
Dependent Claim
66 words
The plasma reactor of claim 28 wherein said induction coil has an opening therein in which windings of said induction coil are absent, said opening facing the interior of said vacuum chamber, and wherein said auxiliary electrode comprises a second portion from which said first portion radiates outwardly, said second portion being a closed surface and being in registration with said opening of said induction coil.
Claim 32
Dependent Claim
17 words
The plasma reactor of claim 29 wherein said second portion is connected to said RF power source.
Claim 33
Dependent Claim
54 words
The plasma reactor of claim 24 further comprising a capacitor having one side thereof connected to said auxiliary electrode and an opposite side of said capacitor connected to a ground terminal of said RF power source, said capacitor providing, in combination with said induction coil, resonance at a frequency of said RF power source.
Claim 34
Dependent Claim
36 words
The plasma reactor of claim 24 further comprising: a wafer pedestal in the interior of said vacuum chamber for supporting said semiconductor substrate thereon; and means for applying a selected electrical potential to said wafer pedestal.
Claim 35
Dependent Claim
137 words
A plasma reactor for carrying out plasma processing of a semiconductor substrate, comprising: a vacuum chamber including means for introducing a gas into the interior thereof; an RF power source; an induction coil facing a region of said vacuum chamber, said coil being connected across said RF power source, and an integrated auxiliary electrode electrically connected to a portion of said induction coil; and wherein said RF power source provides sufficient power to the electrode to ignite the plasma, and provides power to said induction coil; wherein said auxiliary electrode has a surface area suitable to limit capacitive coupling of RF power to said gas in said vacuum chamber so that, during steady-state maintenance of the plasma, most of the RF power coupled to the plasma from said RF power source is coupled inductively rather than capacitively.
Claim 36
Dependent Claim
137 words
A plasma reactor for carrying out plasma processing of a semiconductor substrate, comprising: a vacuum chamber including means for introducing a gas into the interior thereof; an RF power source; an induction coil facing a region of said vacuum chamber, said coil being connected across said RF power source, and an integrated auxiliary electrode electrically connected to a portion of said induction coil; and wherein said RF power source provides sufficient power to the electrode to ignite the plasma, and provides power to said induction coil; wherein said auxiliary electrode has a surface area suitable to limit capacitive coupling of RF power to said gas in said vacuum chamber so that, during steady-state maintenance of the plasma, most of the RF power coupled to the plasma from said RF power source is coupled inductively rather than capacitively.
Claim 37
Dependent Claim
42 words
The plasma reactor of claim 33 wherein a first portion of said auxiliary electrode lies between said induction coil and said vacuum chamber, said first portion having at least an aperture therein to prevent a closed conductive path around said inductive coil.
Claim 38
Dependent Claim
51 words
The plasma reactor of claim 34 wherein said coil comprises a first terminal connected to an energized terminal of said RF power source and a second terminal which is grounded, and wherein said auxiliary electrode further comprises a second portion connected to said induction coil between said first and second terminals.
Claim 39
Dependent Claim
47 words
The plasma reactor of claim 35 wherein: said second portion of said auxiliary electrode comprises a center connection region; and said first portion of said auxiliary electrode comprises plural arms separated by apertures therebetween and radiating outwardly from said center connection region and across said induction coil.
Claim 40
Dependent Claim
58 words
The plasma reactor of claim 36 wherein said center connection region is a closed circular conductive disk, said induction coil having an opening therethrough near the center thereof, said center connection region being in registration with said opening of said induction coil so as to avoid being between said induction coil and the interior of said vacuum chamber.
Claim 41
Dependent Claim
79 words
The plasma reactor of claim 37 wherein said vacuum chamber comprises a sealed container having a circular cross-sectional shape and a top centered at an axis of symmetry of said circular cross-sectional shape, said induction coil being wound around said sealed container so that said opening of said induction coil coincides with said top of said sealed container, and wherein said center connection region of said auxiliary electrode is on said top and centered at said axis of symmetry.
Claim 42
Dependent Claim
22 words
The plasma reactor of claim 38 wherein said auxiliary electrode comprises a film deposited on an exterior surface of said sealed container.
Claim 43
Dependent Claim
35 words
The plasma reactor of claim 39 wherein said sealed container comprises a dome and wherein said top comprises an apex of said dome, and wherein arms of said auxiliary electrode extend downwardly from said apex.
Claim 44
Dependent Claim
26 words
The plasma reactor of claim 39 wherein each of said arms has a width less than 5% of the circumference of the base of said dome.
Claim 45
Dependent Claim
33 words
The plasma reactor of claim 39 wherein said induction coil is wound around a lower portion of said dome so as to leave said opening therethrough centered at said apex of said dome.
Claim 46
Dependent Claim
25 words
The plasma reactor of claim 42 wherein said induction coil is spaced from said dome to accommodate said second portion of said auxiliary electrode therebetween.
Claim 47
Dependent Claim
19 words
The plasma reactor of claim 33 further comprising a capacitor having one side thereof connected to said auxiliary electrode.
Claim 48
Dependent Claim
19 words
The plasma reactor of claim 44 wherein an opposite side of said capacitor is connected to a ground terminal.
References Cited (Backward Citations)
GB1461636A
Cited
US4795880A
Cited
US4786352A
Cited
US4844775A
Cited
US4918031A
Cited
EP0467046A2
Cited
US5460707A
Cited
EP0520519A1
Cited
EP0552490A1
Cited
US5252178A
Cited
US5346578A
Cited
US5449432A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-11-10 | 2001-05-12 | 2001-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-11-10 | 2005-05-12 | 2005-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-11-10 | 2009-05-12 | 2009-11-11 | $7700.00 | Window Closed / Lapsed |