US5350454A
Expired / Lapsed
US
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Plasma processing apparatus for controlling plasma constituents using neutral and plasma sound waves
Assignee: General Atomics Corp
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Filing: 1993-02-26
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Granted: 1994-09-27
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Expires: 2013-02-26
Abstract
Abstract A neutral or plasma sound wave is launched into a plasma used within a plasma processing chamber in order to selectively control the location and concentration of plasma constituents, including (1) contaminants; (2) reactants, including ions or molecules; and/or (3) reaction products. The plasma sound wave comprises a periodic waveform controlled to include at least a second harmonic component. Oseen or Oseen-like forces associated with a neutral or plasma sound wave impart a drift velocity to contaminant particles, e.g., micron-sized dust particles, that moves such particles in a desired direction, e.g., away from a wafer or other work surface being processed by the plasma. An analogous Oseen or Oseen-like force associated with a plasma sound wave imparts a drift velocity to the reactants or reaction products in the plasma so as to move such atomic-sized reactants or products in a desired direction, e.g., proximate the workpiece in the case of the reactants, or removed from the workpiece in the case of the products. The drift velocity, including its direction, is controlled by controlling the harmonic content, intensity and/or phase of the neutral or plasma sound wave.
Inventors
- 👤 Tihiro Ohkawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:09
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/32798; H01J37/32853; H01J37/32862; C; C23; C23C; C23C16/00; C23C16/44; C23C16/4401; C23C16/4415; H01J2237/00; H01J2237/02; H01J2237/022; Y; Y10; Y10S; Y10S156/00; Y10S156/916
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
153 words
Plasma processing apparatus comprising: a plasma processing chamber; means for introducing a prescribed gas into said plasma processing chamber; means for establishing and maintaining a plasma from said gas within said plasma processing chambers, said plasma processing chamber including a workpiece to be processed by said plasma; launching means for launching a periodic sound wave into said plasma, said sound wave being characterized by an intensity and fundamental frequency and harmonic content that includes at least a second harmonic, said sound wave interacting with a constituent within said plasma so as to impart a drift velocity thereto; control means for controlling the characteristics of said sound wave so as to cause said constituent to move within said plasma as a result of said drift velocity in a desired direction within said plasma processing chamber; whereby the location and flow of said constituent within said plasma may be controlled by controlling said sound wave.
Claim 2
Dependent Claim
153 words
Plasma processing apparatus comprising: a plasma processing chamber; means for introducing a prescribed gas into said plasma processing chamber; means for establishing and maintaining a plasma from said gas within said plasma processing chambers, said plasma processing chamber including a workpiece to be processed by said plasma; launching means for launching a periodic sound wave into said plasma, said sound wave being characterized by an intensity and fundamental frequency and harmonic content that includes at least a second harmonic, said sound wave interacting with a constituent within said plasma so as to impart a drift velocity thereto; control means for controlling the characteristics of said sound wave so as to cause said constituent to move within said plasma as a result of said drift velocity in a desired direction within said plasma processing chamber; whereby the location and flow of said constituent within said plasma may be controlled by controlling said sound wave.
Claim 3
Dependent Claim
34 words
The plasma processing apparatus as set forth in claim 1 wherein said launching means comprises an antenna structure positioned within said plasma chamber and means for applying an oscillating voltage to said antenna structure.
Claim 4
Dependent Claim
55 words
The plasma processing apparatus as set forth in claim 2 wherein said plasma processing chamber has a longitudinal axis, and wherein said antenna structure is positioned near the center of said plasma processing chamber and is oriented so as to excite a neutral or plasma sound wave that propagates substantially parallel to said longitudinal axis.
Claim 5
Dependent Claim
57 words
The plasma processing apparatus as set forth in claim 2 wherein said plasma processing chamber has a longitudinal axis, and wherein said antenna structure is positioned within and near one end of said plasma processing chamber, and is oriented so as to excite a neutral or plasma sound wave that propagates substantially parallel to said longitudinal axis.
Claim 6
Dependent Claim
55 words
The plasma processing apparatus as set forth in claim 2 wherein said plasma processing chamber has a longitudinal axis, and wherein said antenna structure is positioned within and near one side of said plasma processing chamber, and is oriented so as to excite a plasma sound wave that propagates substantially perpendicular to said longitudinal axis.
Claim 7
Dependent Claim
53 words
The plasma processing apparatus as set forth in claim 2 wherein said plasma processing chamber has a longitudinal axis, and wherein said antenna structure is positioned near the center of said plasma processing chamber, and is oriented so as to excite a plasma sound wave that propagates substantially perpendicular to said longitudinal axis.
Claim 8
Dependent Claim
18 words
The plasma processing apparatus as set forth in claim 2 wherein said antenna structure comprises spaced-apart conductive electrodes.
Claim 9
Dependent Claim
20 words
The plasma processing apparatus as set forth in claim 7 wherein said conductive electrodes include a conductive grid of wires.
Claim 10
Dependent Claim
25 words
The plasma processing apparatus as set forth in claim 2 wherein said antenna structure comprises a single conductive electrode comprising a conductive grid of wires.
Claim 11
Dependent Claim
24 words
The plasma processing apparatus as set forth in claim 2 wherein said antenna structure comprises a loudspeaker that launches a neutral gas sound wave.
Claim 12
Dependent Claim
30 words
The plasma processing apparatus as set forth in claim 1 wherein said constituent that is moved within said plasma as a result of said drift velocity comprises a contaminant particle.
Claim 13
Dependent Claim
39 words
The plasma processing apparatus as set forth in claim 11 wherein said control means controls the characteristics of said sound wave so as to impart a drift velocity to said contaminant particles that moves them away from said workpiece.
Claim 14
Dependent Claim
43 words
The plasma processing apparatus as set forth in claim 1 wherein said sound wave comprises a plasma sound wave, and wherein said constituent that is moved within said plasma as a result of said drift velocity comprises atomic-sized reactants, including ions and molecules.
Claim 15
Dependent Claim
39 words
The plasma processing apparatus as set forth in claim 13 wherein said control means controls the characteristics of said plasma sound wave so as to impart a drift velocity to said atomic-sized reactants that moves them towards said workpiece.
Claim 16
Dependent Claim
52 words
The plasma processing apparatus as set forth in claim 1 wherein said sound wave comprises a plasma sound wave, and wherein said constituent that is moved within said plasma as a result of said drift velocity comprises atomic-sized products created by a chemical reaction between reactants within said plasma and the workpiece.
Claim 17
Dependent Claim
40 words
The plasma processing apparatus as set forth in claim 15 wherein said control means controls the characteristics of said plasma sound wave so as to impart a drift velocity to said atomic-sized products that moves them away from said workpiece.
Claim 18
Dependent Claim
42 words
The plasma processing apparatus as set forth in claim 1 wherein said constituent that is moved within said plasma as a result of said drift velocity comprises at least one of: contaminant particles; atomic-sized reactants, including ions and molecules; and atomic-sized products.
Claim 19
Dependent Claim
59 words
The plasma processing apparatus as set forth in claim 17 wherein said control means controls the characteristics of said sound wave so as to impart a drift velocity to: said contaminant particles that moves them away from said workpiece, said atomic-sized reactants that moves them towards said workpiece, and said atomic-sized products that moves them away from said workpiece.
Claim 20
Dependent Claim
93 words
Plasma processing apparatus comprising: a plasma processing chamber; means for establishing and maintaining a plasma within said plasma processing chamber; a workpiece positioned within said plasma processing chamber to be processed by said plasma; and launching means for launching a sound wave into said plasma, said sound wave being characterized by an intensity and fundamental frequency and harmonic content that includes at least a second harmonic, said sound wave interacting with contaminant particles within said plasma so as to impart a drift velocity thereto that carries said contaminant particles away from said workpiece.
Claim 21
Dependent Claim
93 words
Plasma processing apparatus comprising: a plasma processing chamber; means for establishing and maintaining a plasma within said plasma processing chamber; a workpiece positioned within said plasma processing chamber to be processed by said plasma; and launching means for launching a sound wave into said plasma, said sound wave being characterized by an intensity and fundamental frequency and harmonic content that includes at least a second harmonic, said sound wave interacting with contaminant particles within said plasma so as to impart a drift velocity thereto that carries said contaminant particles away from said workpiece.
Claim 22
Dependent Claim
25 words
The plasma processing apparatus as set forth in claim 19 wherein said launching means comprises means for launching a neutral sound wave into said plasma.
Claim 23
Dependent Claim
25 words
The plasma processing apparatus as set forth in claim 19 wherein said launching means comprises means for launching a plasma sound wave into said plasma.
Claim 24
Dependent Claim
100 words
Plasma processing apparatus comprising: a plasma processing chamber; means for establishing and maintaining a plasma within said plasma processing chamber; a workpiece positioned within said plasma processing chamber to be processed by said plasma; and launching means for launching a plasma sound wave into said plasma, said plasma sound wave being characterized by an intensity and fundamental frequency and harmonic content that includes at least a second harmonic, said plasma sound wave interacting with atomic-sized reactants, including ions and molecules, within said plasma so as to impart a drift velocity thereto that carries said atomic-sized reactants towards from said workpiece.
Claim 25
Dependent Claim
100 words
Plasma processing apparatus comprising: a plasma processing chamber; means for establishing and maintaining a plasma within said plasma processing chamber; a workpiece positioned within said plasma processing chamber to be processed by said plasma; and launching means for launching a plasma sound wave into said plasma, said plasma sound wave being characterized by an intensity and fundamental frequency and harmonic content that includes at least a second harmonic, said plasma sound wave interacting with atomic-sized reactants, including ions and molecules, within said plasma so as to impart a drift velocity thereto that carries said atomic-sized reactants towards from said workpiece.
Claim 26
Dependent Claim
102 words
Plasma processing apparatus comprising: a plasma processing chamber; means for establishing and maintaining a plasma within said plasma processing chamber; a workpiece positioned within said plasma processing chamber to be processed by said plasma; and launching means for launching a plasma sound wave into said plasma, said plasma sound wave being characterized by an intensity and fundamental frequency and harmonic content that includes at least a second harmonic, said plasma sound wave interacting with atomic-sized products that result from said plasma reacting with said workpiece so as to impart a drift velocity thereto that carries said atomic-sized products away from said workpiece.
Claim 27
Dependent Claim
102 words
Plasma processing apparatus comprising: a plasma processing chamber; means for establishing and maintaining a plasma within said plasma processing chamber; a workpiece positioned within said plasma processing chamber to be processed by said plasma; and launching means for launching a plasma sound wave into said plasma, said plasma sound wave being characterized by an intensity and fundamental frequency and harmonic content that includes at least a second harmonic, said plasma sound wave interacting with atomic-sized products that result from said plasma reacting with said workpiece so as to impart a drift velocity thereto that carries said atomic-sized products away from said workpiece.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-09-26 | 1998-03-28 | 1998-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-26 | 2002-03-28 | 2002-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-26 | 2006-03-28 | 2006-09-27 | $7700.00 | Window Closed / Lapsed |