Patent US3547241A successfully refreshed from Google Patents.
Patent US5038013A successfully refreshed from Google Patents.
US5038013A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma processing apparatus including an electromagnet with a bird cage core
Assignee: Mitsubishi Electric Corp
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Filing: 1990-08-03
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Granted: 1991-08-06
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Expires: 2010-08-03
Abstract
Abstract A plasma etching apparatus comprises a chamber, a holding table for holding samples, such as a semiconductor substrate to be etched, in the chamber, a plasma-generating device for generating a plasma within the chamber, and a magnetic-field-forming device which forms a magnetic field perpendicular to the surface of the sample placed on the holding table and parallel the inner wall of the chamber.
Inventors
- 👤 Moriaki Akazawa
- 👤 Takahiro Maruyama
- 👤 Toshiaki Ogawa
- 👤 Hiroshi Morita
- 👤 Tomoaki Ishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:37
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/32623; H01J37/3266; H01J37/32688
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
136 words
A plasma etching apparatus comprising: a chamber having a central axis and an inner wall generally parallel to the central axis; holding means for holding a sample in said chamber generally perpendicular to said inner wall; plasma-generating means for generating a plasma within said chamber; and magnetic-field-forming means for forming a magnetic field generally perpendicular to a sample placed on said holding means and generally parallel to said inner wall of said chamber comprising a substantially cylindrical electromagnet coaxial with said chamber and including a magnetic core having a pair of annular members disposed generally perpendicular to the central axis and a plurality of post members generally parallel to the central axis joining said pair of annular members, and a plurality of coils, each coil wound around one of said post members of said magnetic core.
Claim 2
Dependent Claim
136 words
A plasma etching apparatus comprising: a chamber having a central axis and an inner wall generally parallel to the central axis; holding means for holding a sample in said chamber generally perpendicular to said inner wall; plasma-generating means for generating a plasma within said chamber; and magnetic-field-forming means for forming a magnetic field generally perpendicular to a sample placed on said holding means and generally parallel to said inner wall of said chamber comprising a substantially cylindrical electromagnet coaxial with said chamber and including a magnetic core having a pair of annular members disposed generally perpendicular to the central axis and a plurality of post members generally parallel to the central axis joining said pair of annular members, and a plurality of coils, each coil wound around one of said post members of said magnetic core.
Claim 3
Dependent Claim
13 words
A plasma etching apparatus according to claim 1, wherein said chamber is cylindrical.
Claim 4
Dependent Claim
29 words
A plasma etching apparatus according to claim 1, wherein each of said annular members includes an annular projection protruding along said inner wall of said chamber toward said chamber.
Claim 5
Dependent Claim
21 words
A plasma etching apparatus according to claim 3, wherein said projections of said annular members are disposed outside of said chamber.
Claim 6
Dependent Claim
19 words
A plasma etching apparatus according to claim 3, wherein said projections of said annular members protrude into said chamber.
Claim 7
Dependent Claim
69 words
A plasma etching apparatus according to claim 1, wherein said plasma-generating means comprises a pair of electrode plates coaxial with the central axis of said chamber and disposed within said chamber, opposing each other, a power source for applying a voltage between said pair of electrode plates, a gas feeding device for feeding reaction gases to said chamber and a gas discharging device for discharging gases from said chamber
Claim 8
Dependent Claim
19 words
A plasma etching apparatus according to claim 6, wherein said holding means is one of said two electrode plates.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-05 | 1995-02-04 | 1995-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-05 | 1999-02-04 | 1999-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-05 | 2003-02-04 | 2003-08-06 | $7700.00 | Window Closed / Lapsed |