US4116793A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glow discharge method and apparatus
Assignee: Dart Industries Inc
•
Filing: 1977-05-31
•
Granted: 1978-09-26
•
Expires: 1997-05-31
Abstract
Abstract A method and apparatus for providing a completely closed plasma trap in an r.f. type glow discharge system to enable enhanced sputtering from a pair of electrodes so that substrates may be suitably coated. The electrode pairs may be post type, hollow or planar, in various shapes with and without end wings. All configurations utilize a cooperating magnetic field, provided by field coils external or internal to the electrodes, the magnetic field being shaped to define with the electrodes at least one plasma containing trap having axial symmetry imposed by the magnetic field and/or the electrode structure. The trap may be defined by the pair of electrodes acting in concert with each other and the magnetic field, one or more traps may be defined separately by each electrode and the magnetic field, or both types of traps may exist simultaneously in a hybrid situation. Means are also disclosed for mounting, centering, cooling, assembling and making electrical contact with various of the electrode structures. Means are further disclosed for protecting various structural elements from undesired exposure to plasma, preventing conductive plating of insulators, due to undesired deposition of target material, and shielding the entire glow discharge system to prevent undesired r.f. radiation leakage to the surrounding environment.
Inventors
- 👤 Alan S. Penfold
- 👤 John A. Thornton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:43
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/34; H01J37/3402
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
62 words
A method of generating a glow discharge, comprising the steps of: supporting a pair of planar electrodes within a working gas environment; applying electrical voltage across said electrodes; and forming a magnetic field which defines, together with said electrodes, at least one trap for containing substantially all electrons emitted from said electrodes and having sufficient energy to further ionize said working gas.
Claim 2
Independent Claim
62 words
A method of generating a glow discharge, comprising the steps of: supporting a pair of planar electrodes within a working gas environment; applying electrical voltage across said electrodes; and forming a magnetic field which defines, together with said electrodes, at least one trap for containing substantially all electrons emitted from said electrodes and having sufficient energy to further ionize said working gas.
Claim 3
Dependent Claim
13 words
A method as set forth in claim 1, wherein said electrodes are coplanar.
Claim 4
Dependent Claim
24 words
A method as set forth in claim 1, and further including: maintaining said working gas environment at a pressure of 1 micron or less.
Claim 5
Dependent Claim
15 words
A method as set forth in claim 1, wherein said voltage is an r.f. voltage.
Claim 6
Dependent Claim
19 words
A method as set forth in claim 1, wherein said trap has axial symmetry about an axis of rotation,
Claim 7
Dependent Claim
21 words
A method as set forth in claim 1, wherein said electrodes include a sputtering surface comprised of an electrically conductive material.
Claim 8
Dependent Claim
21 words
A method as set forth in claim 1, wherein said electrodes include a sputtering surface comprised of an electrically insulating material.
Claim 9
Dependent Claim
13 words
A method as set forth in claim 1, wherein said electrodes are coaxial.
Claim 10
Dependent Claim
79 words
Glow discharge apparatus, comprising: a pair of planar electrodes; mounting means for supporting said electrodes in close, spaced apart relationship in a low pressure working gas environment; power supply means for supplying an electrical voltage across said pair of electrodes; and magnetic field means for forming a magnetic field which defines with said electrodes at least one completely closed trap for containing substantially all electrons emitted from said electrodes and having sufficient energy to further ionize said working gas.
Claim 11
Dependent Claim
79 words
Glow discharge apparatus, comprising: a pair of planar electrodes; mounting means for supporting said electrodes in close, spaced apart relationship in a low pressure working gas environment; power supply means for supplying an electrical voltage across said pair of electrodes; and magnetic field means for forming a magnetic field which defines with said electrodes at least one completely closed trap for containing substantially all electrons emitted from said electrodes and having sufficient energy to further ionize said working gas.
Claim 12
Dependent Claim
28 words
Apparatus as set forth in claim 9, wherein one of said electrodes is a disc and the other of said electrodes is a ring concentric with said disc.
Claim 13
Dependent Claim
12 words
Apparatus as set forth in claim 10 wherein said electrodes are coplanar.
Claim 14
Dependent Claim
26 words
A combination as set forth in claim 10, wherein said electrodes are disposed in a working gas environment at a pressure of 1 micron or less.
Claim 15
Dependent Claim
15 words
A combination as set forth in claim 10, wherein said voltage is an r.f. voltage.
Claim 16
Dependent Claim
24 words
A combination as set forth in claim 10, wherein said electrodes include a sputtering surface adapted to be comprised of an electrically conductive material.
Claim 17
Dependent Claim
24 words
A combination as set forth in claim 10, wherein said electrodes include a sputtering surface adapted to be comprised of an electrically insulating material.
Claim 18
Dependent Claim
14 words
Apparatus as set forth in claim 9, wherein each of said electrodes is semicircular
Claim 19
Dependent Claim
12 words
Apparatus as set forth in claim 16 wherein said electrodes are coplanar.
Claim 20
Dependent Claim
12 words
Apparatus as set forth in claim 9, wherein said electrodes are coplanar.
Claim 21
Dependent Claim
26 words
A combination as set forth in claim 9, wherein said electrodes are disposed in a working gas environment at a pressure of 1 micron or less.
Claim 22
Dependent Claim
15 words
A combination as set forth in claim 9, wherein said voltage is an r.f. voltage.
Claim 23
Dependent Claim
24 words
A combination as set forth in claim 9, wherein said electrodes include a sputtering surface adapted to be comprised of an electrically conductive material.
Claim 24
Dependent Claim
24 words
A combination as set forth in claim 9, wherein said electrodes include a sputtering surface adapted to be comprised of an electrically insulating material.
Claim 25
Dependent Claim
50 words
In an r.f. glow discharge system, the combination comprising: a pair of planar electrodes; and means for forming a magnetic field which defines with said electrode assembly at least one completely closed trap for containing substantially all electrons emitted from said electrodes and having sufficient energy to create additional ions.
Claim 26
Dependent Claim
50 words
In an r.f. glow discharge system, the combination comprising: a pair of planar electrodes; and means for forming a magnetic field which defines with said electrode assembly at least one completely closed trap for containing substantially all electrons emitted from said electrodes and having sufficient energy to create additional ions.
Claim 27
Dependent Claim
28 words
Apparatus as set forth in claim 23 wherein one of said electrodes is a disc and the other of said electrodes is a ring concentric with said disc.
Claim 28
Dependent Claim
14 words
Apparatus as set forth in claim 23, wherein each of said electrodes is semicircular.
References Cited (Backward Citations)
US3325394A
Cited
GB1169747A
Cited
GB1169748A
Cited
US3669861A
Cited
US3676320A
Cited
US3669860A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-25 | 1982-03-27 | 1982-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-25 | 1986-03-27 | 1986-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-25 | 1990-03-27 | 1990-09-26 | $7700.00 | Window Closed / Lapsed |