EP0286132A2
Expired / Lapsed
EP
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Plasma generating apparatus
Assignee: Hitachi Ltd
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Filing: 1988-04-08
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Granted: —
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Expires: 2008-04-08
Abstract
Abstract An apparatus for generating plasma by making use of electron cyclotron resonance employs permanent magnets (65) for forming magnetic fields, and the permanent magnets are arranged in such a manner as to form stronger magnetic fields in peripheral portion of a plasma chamber (51) than in a central portion of the same. Furthermore, electrons are introduced into an additional plasma chamber (52) in which an electric field is not applied so as to generate low-temperature plasma.
Inventors
- 👤 Yoshimi Hakamata
- 👤 Ken-Ichi Natsui
- 👤 Yukio Kurosawa
- 👤 Tadashi Sato
- 👤 Hiroaki Kojima
- 👤 Yasunori Ohno
- 👤 Tomoe Kurosawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 18:14
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/02; H05H1/04; H05H1/08; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32357
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
108 words
A plasma generating apparatus for generating plasma in a plasma generating chamber (1) by introducing microwaves into said plasma generating chamber (1) filled with a lean gas and by causing a magnetic field in the same direction as the advancing direction of said microwaves to act in said chamber by magnetic field generating means (21), characterized in that the intensity of said magnetic field is formed in such a manner as to be stronger in an inner peripheral portion of said chamber (1) than in a central portion of said chamber (1) in a cross section of said chamber (1) perpendicular to the advancing direction of said microwaves.
Claim 2
Dependent Claim
108 words
A plasma generating apparatus for generating plasma in a plasma generating chamber (1) by introducing microwaves into said plasma generating chamber (1) filled with a lean gas and by causing a magnetic field in the same direction as the advancing direction of said microwaves to act in said chamber by magnetic field generating means (21), characterized in that the intensity of said magnetic field is formed in such a manner as to be stronger in an inner peripheral portion of said chamber (1) than in a central portion of said chamber (1) in a cross section of said chamber (1) perpendicular to the advancing direction of said microwaves.
Claim 3
Dependent Claim
23 words
A plasma generating apparatus according to Claim 1, wherein said magnetic field generating device (21) is a permanent magnet disposed outside said chamber.
Claim 4
Dependent Claim
29 words
A plasma generating apparatus according to Claim 2, wherein at least one set of permanent magnets (21a, 21b) are arranged with mutually different polarities opposing a plasma generating portion.
Claim 5
Dependent Claim
43 words
A plasma generating apparatus according to Claims 1 to 3, wherein said intensity of said magnetic field is sufficiently large to cause electron cyclotron resonance to take place at a frequency of said microwaves in at least a part of said chamber (1)
Claim 6
Dependent Claim
46 words
A plasma generating apparatus according to Claims 1 to 4, wherein a cross-sectional area of said plasma generating chamber (1) perpendicular to the advancing direction of said microwaves increases substantially continuously from a microwave introducing portion of said chamber (1) the advancing direction of said microwaves.
Claim 7
Dependent Claim
75 words
A plasma generating apparatus according to Claim 5, wherein a plasma storing chamber (43) having a cross-sectional area which is larger than a maximal cross-sectional area of said chamber (1) is provided in such a manner as to communicate with said chamber (1), and a plurality of permanent magnets (42) are arranged around the outer periphery of said storing chamber (43) in such a manner that polarities of adjacent magnets are opposite to each other.
Claim 8
Dependent Claim
183 words
A plasma generating apparatus according to Claims 1 to 5, wherein a main plasma generating chamber (52) is disposed adjacent to said plasma generating chamber (51) such as to allow said lean gas to pass between said two chambers (51, 52) while maintaining electrical insulation between said two chambers; electron extraction electrodes (56, 57) constituted by a first electrode (56) and a second electrode (57) are provided such as to oppose each other, said first electrode (56) being located on the side of said plasma generating chamber (51) and electrically connected to said plasma generating chamber (51), said second electrode (57) being located on the side of said main plasma generating chamber (52) and connected to said main plasma generating chamber (52); a potential difference is imparted between said first and second electrodes (56, 57) in such a manner that said second electrode (57) becomes positive; electrons are taken out of said plasma generating chamber (51) into said main plasma generating chamber (52) and are caused to collide against said lean gas in said main plasma generating chamber (52), thereby generating low-temperature plasma.
Claim 9
Dependent Claim
56 words
A plasma generating apparatus according to Claim 7, wherein a plurality of permanent magnets (65) are arranged around said outer periphery of said main plasma generating chamber (52) in such a manner that the N pole and the S pole of the magnets are alternately opposed to the inside of said main plasma generating chamber (52).
Claim 10
Dependent Claim
31 words
A plasma generating apparatus according to Claims 7 and 8, wherein said electron extraction electrodes (71, 72) are formed into a convex shape protruding into said main plasma generating chamber (52).
References Cited (Backward Citations)
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