US5404079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma generating apparatus
Assignee: RPX Corp
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Filing: 1993-07-27
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Granted: 1995-04-04
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Expires: 2013-07-27
Abstract
Abstract On the inner surface of a chamber are circumferentially disposed three lateral electrodes at regular intervals. To the lateral electrodes are applied three high-frequency electric powers of 50 MHz, each differing in phase by approximately 120°. On the bottom of the chamber is placed a sample stage serving as a second electrode, around which is provided a ring-shaped earth electrode. To the sample stage is applied high-frequency electric power of 13.56 MHz. The distance between each of the three lateral electrodes and the earth electrode is longer than the distance between the sample stage and the earth electrode.
Inventors
- 👤 Mitsuhiro Ohkuni
- 👤 Masafumi Kubota
- 👤 Noboru Nomura
- 👤 Ichiro Nakayama
- 👤 Tokuhiko Tamaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:36
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32082; H01J37/32137; H01J37/32155; H01J37/32165; H01J37/32431; H01J37/32532; H01J37/32541; H10; H10P; H10P72/00; H10P72/04; H10P72/0402
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
187 words
A plasma generating apparatus comprising: a vacuum chamber; plasma generating means including N first electrodes (N is an integer not less than 2) disposed at roughly regular intervals in said vacuum chamber and a first high-frequency power supply for supplying said first electrodes in the order of their arrangement with high-frequency electric powers, each of which has a first frequency but differs in phase by (360/N) degrees, so as generate, by means of a rotating electric field formed by said first electrodes, a highly dense plasma in a plasma generating part surrounded by said first electrodes; and ion extracting means including a second electrode, an earth electrode, both of which are disposed in said vacuum chamber, and a second high-frequency power supply for supplying said second electrode with high-frequency electric power having a second frequency so as to extract ions from the plasma which has been generated in said plasma generating part, said earth electrode being placed in such a position that an electric field formed between said earth electrode and said second electrode does not interfere with the rotating electric field formed by said first electrodes.
Claim 2
Dependent Claim
187 words
A plasma generating apparatus comprising: a vacuum chamber; plasma generating means including N first electrodes (N is an integer not less than 2) disposed at roughly regular intervals in said vacuum chamber and a first high-frequency power supply for supplying said first electrodes in the order of their arrangement with high-frequency electric powers, each of which has a first frequency but differs in phase by (360/N) degrees, so as generate, by means of a rotating electric field formed by said first electrodes, a highly dense plasma in a plasma generating part surrounded by said first electrodes; and ion extracting means including a second electrode, an earth electrode, both of which are disposed in said vacuum chamber, and a second high-frequency power supply for supplying said second electrode with high-frequency electric power having a second frequency so as to extract ions from the plasma which has been generated in said plasma generating part, said earth electrode being placed in such a position that an electric field formed between said earth electrode and said second electrode does not interfere with the rotating electric field formed by said first electrodes.
Claim 3
Dependent Claim
35 words
A plasma generating apparatus according to claim 1, wherein said first electrodes are placed on the lateral part of said vacuum chamber and said second electrode is placed on the bottom of said vacuum chamber.
Claim 4
Dependent Claim
26 words
A plasma generating apparatus according to claim 2, wherein said earth electrode is formed in the shape of a ring and provided around said second electrode.
Claim 5
Dependent Claim
34 words
A plasma generating apparatus according to claim 1, wherein the distance between each of said first electrodes and said earth electrode is longer than the distance between said second electrode and said earth electrode.
Claim 6
Dependent Claim
39 words
A plasma generating apparatus according to claim 1, wherein the first frequency of the high-frequency electric powers applied to said first electrodes is set higher than the second frequency of the high-frequency electric power applied to said second electrode.
Claim 7
Dependent Claim
18 words
A plasma generating apparatus according to claim 1, wherein the inner surface of said vacuum chamber is insulated.
Claim 8
Dependent Claim
29 words
A plasma generating apparatus according to claim 1, wherein the surfaces of said first electrodes are covered with insulating protective films for preventing sputter deposition on said first electrodes.
Claim 9
Dependent Claim
22 words
A plasma generating apparatus according to claim 1, wherein the pressure in said vacuum chamber is set at 10 Pa or less.
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) | 1998-04-03 | 1998-10-03 | 1999-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-04-03 | 2002-10-03 | 2003-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-04-03 | 2006-10-03 | 2007-04-04 | $7700.00 | Window Closed / Lapsed |