US5998933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
RF plasma inductor with closed ferrite core
Assignee: Advanced Energy Industries Inc
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Filing: 1998-04-06
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Granted: 1999-12-07
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Expires: 2018-04-06
Abstract
Abstract The present invention pertains to RF (radio frequency) inductive coupling plasma (ICP) inductors having an actual primary winding (powered directly by an RF source) wound around a closed ferrite core, and a virtual closed secondary winding formed around this ferrite core in a plasma contained within a discharge chamber. The present invention enables one to maintain a uniform plasma with no limitation in process sizes and assumes a variety of embodiments. The simplest is merely an annular ferrite core having a primary winding (a few turns) which is placed into the discharge chamber filled with a necessary gas. The plasma sources based on the present invention can be applied in plasma processing technology: etching, deposition, ion implantation, abatement, etc. in plasma devices from ten Watts to a few kW, at an operating frequency from 100 kHz to a few MHZ, and at linear sizes from a few centimeters to a few meters.
Inventors
- 👤 Evgeny V. Shun'ko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:19
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32082; H01J37/321; H05; H05H; H05H1/00; H05H1/24; H05H1/46
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
51 words
An inductive coupling plasma inductor comprising: an actual primary winding powered directly from a radio frequency source, and a closed ferrite core disposed in said primary winding and positioned relative to a plasma charged discharge chamber for providing a virtual closed secondary winding formed around all surfaces of said ferrite core.
Claim 2
Dependent Claim
51 words
An inductive coupling plasma inductor comprising: an actual primary winding powered directly from a radio frequency source, and a closed ferrite core disposed in said primary winding and positioned relative to a plasma charged discharge chamber for providing a virtual closed secondary winding formed around all surfaces of said ferrite core.
Claim 3
Dependent Claim
16 words
An inductive coupling plasma inductor as recited in claim 1 wherein said ferrite core is circular.
Claim 4
Dependent Claim
16 words
An inductive coupling plasma inductor as recited in claim 1 wherein said ferrite core is rectangular.
Claim 5
Dependent Claim
42 words
An inductive coupling plasma inductor as recited in claim 1 including a metallic cooling jacket enclosing said ferrite core, said jacket having an electrical gap around said core, and having an inlet and an outlet for passing a coolant through said jacket.
Claim 6
Dependent Claim
22 words
An inductive coupling plasma inductor as recited in claim 1 wherein said ferrite core is retained in position by said primary winding.
Claim 7
Dependent Claim
42 words
An inductive coupling plasma inductor as recited in claims 1, including a plurality of said closed ferrite cores disposed respectively in a plurality of said primary windings and arranged in an assembly for providing a uniform plasma distribution about a required area.
Claim 8
Dependent Claim
86 words
An inductive coupling plasma inductor comprising: an actual primary winding powered directly from a radio frequency source, a closed ferrite core disposed in said primary winding and positioned relative to a plasma charged discharge chamber for providing a virtual closed secondary winding formed in said plasma around said ferrite core, and wherein said ferite core is separated from said discharge chamber by a nonconductive jacket crossing said discharge chamber and wherein only small portions of said ferrite core are exposed out side of said discharge chamber.
Claim 9
Dependent Claim
86 words
An inductive coupling plasma inductor comprising: an actual primary winding powered directly from a radio frequency source, a closed ferrite core disposed in said primary winding and positioned relative to a plasma charged discharge chamber for providing a virtual closed secondary winding formed in said plasma around said ferrite core, and wherein said ferite core is separated from said discharge chamber by a nonconductive jacket crossing said discharge chamber and wherein only small portions of said ferrite core are exposed out side of said discharge chamber.
References Cited (Backward Citations)
JPH02260399A
Cited
JPH05144594A
Cited
JPH05166595A
Cited
US5290382A
Cited
US5560776A
Cited
US5464476A
Cited
US5619103A
Cited
US5591493A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-12-06 | 2003-06-07 | 2003-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-12-06 | 2007-06-07 | 2007-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-12-06 | 2011-06-07 | 2011-12-07 | $7700.00 | Window Closed / Lapsed |