US4116794A
Expired / Lapsed
US
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Glow discharge method and apparatus
Assignee: Dart Industries Inc
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Filing: 1977-05-31
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Granted: 1978-09-26
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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
2026-11-05 23:48
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/34; H01J37/3402
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
76 words
A method of generating a glow discharge internally of a pair of hollow electrodes, comprising the steps of: supporting a pair of hollow electrodes in end to end relationship within a working gas environment; applying electrical voltage across said pair of 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
76 words
A method of generating a glow discharge internally of a pair of hollow electrodes, comprising the steps of: supporting a pair of hollow electrodes in end to end relationship within a working gas environment; applying electrical voltage across said pair of 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
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 4
Dependent Claim
15 words
A method as set forth in claim 1, wherein said voltage is an r.f. voltage.
Claim 5
Dependent Claim
19 words
A method as set forth in claim 1, wherein said trap has axial symmetry about an axis of rotation.
Claim 6
Dependent Claim
18 words
A method as set forth in claim 1, wherein said magnetic field is formed from within said electrodes.
Claim 7
Dependent Claim
21 words
A method as set forth in claim 1, wherein said magnetic field is formed from a location external to said electrodes.
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 conductive material.
Claim 9
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 10
Dependent Claim
13 words
A method as set forth in claim 1, wherein said electrodes are coaxial.
Claim 11
Dependent Claim
19 words
A method as set forth in claim 1, wherein each of said electrodes defines a conical surface of revolution.
Claim 12
Dependent Claim
23 words
A method as set forth in claim 1, wherein said magnetic field is formed to define separate traps with each of said electrodes.
Claim 13
Dependent Claim
26 words
A method as set forth in claim 1, wherein said magnetic field is formed to define a single trap with both of said electrodes in concert.
Claim 14
Dependent Claim
22 words
A method as set forth in claim 1, wherein each electrode has an inwardly extending end wing at its outermost distal end.
Claim 15
Dependent Claim
22 words
A method as set forth in claim 1, wherein each electrode has an inwardly extending end wing at its innermost proximal end.
Claim 16
Dependent Claim
50 words
A method as set forth in claim 1, wherein each of said electrodes is coaxial and includes inwardly extending wings at remote outer distal ends and at the innermost proximal ends of said electrodes, the outer wings extending further towards the common axis of said electrodes than the inner wings.
Claim 17
Dependent Claim
116 words
Glow discharge apparatus comprising: a pair of electrodes arranged end to end and separated by an insulator wherein said electrodes are hollow and said glow discharge is generated internally of said electrodes, and each electrode has an inwardly extending end wing at its outermost distal end; 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 18
Dependent Claim
116 words
Glow discharge apparatus comprising: a pair of electrodes arranged end to end and separated by an insulator wherein said electrodes are hollow and said glow discharge is generated internally of said electrodes, and each electrode has an inwardly extending end wing at its outermost distal end; 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 19
Dependent Claim
29 words
Apparatus as set forth in claim 16, wherein each of said electrodes defines a conical surface of revolution, the electrode surfaces of widest diameter being closest to each other.
Claim 20
Dependent Claim
114 words
Glow discharge apparatus comprising: a pair of electrodes arranged end to end and separated by an insulator wherein said electrodes are hollow and said glow discharge is generated internally of said electrodes, each electrode including an inwardly extending wing at its innermost proximal end; 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 21
Dependent Claim
114 words
Glow discharge apparatus comprising: a pair of electrodes arranged end to end and separated by an insulator wherein said electrodes are hollow and said glow discharge is generated internally of said electrodes, each electrode including an inwardly extending wing at its innermost proximal end; 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 22
Dependent Claim
29 words
Apparatus as set forth in claim 18, wherein each of said electrodes defines a conical surface of revolution, the electrode surfaces of widest diameter being closest to each other.
Claim 23
Dependent Claim
118 words
Glow discharge apparatus comprising: a pair of hollow electrodes arranged end to end and separated by an insulator, each of said electrodes being coaxial and including inwardly extending wings at remote outer distal ends and further include additional inwardly extending wings at the innermost proximal ends of said 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 24
Dependent Claim
118 words
Glow discharge apparatus comprising: a pair of hollow electrodes arranged end to end and separated by an insulator, each of said electrodes being coaxial and including inwardly extending wings at remote outer distal ends and further include additional inwardly extending wings at the innermost proximal ends of said 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 25
Dependent Claim
29 words
Apparatus as set forth in claim 20, wherein each of said electrodes defines a conical surface of revolution, the electrode surfaces of widest diameter being closest to each other.
Claim 26
Dependent Claim
65 words
In an r.f. glow discharge system, the combination comprising: a pair of hollow electrodes arranged in end to end relationship wherein said glow discharge is generated internally of said electrodes; and 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 create additional ions.
Claim 27
Dependent Claim
65 words
In an r.f. glow discharge system, the combination comprising: a pair of hollow electrodes arranged in end to end relationship wherein said glow discharge is generated internally of said electrodes; and 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 create additional ions.
Claim 28
Dependent Claim
25 words
A combination as set forth in claim 22, wherein said electrodes are disposed in a gaseous environment at a pressure of one micron or less.
Claim 29
Dependent Claim
19 words
A combination as set forth in claim 22, wherein said trap has axial symmetry about an axis of rotation.
Claim 30
Dependent Claim
24 words
A combination as set forth in claim 22, and further including: means for electrically shielding said electrodes and said glow discharge against r.f. leakage.
Claim 31
Dependent Claim
21 words
A combination as set forth in claim 22, wherein said means for forming said magnetic field is external of said electrodes.
Claim 32
Dependent Claim
22 words
A combination as set forth in claim 22, wherein said magnetic field defines a single separate trap with each of said electrodes.
Claim 33
Dependent Claim
23 words
A combination as set forth in claim 22, wherein said magnetic field defines a single trap with both of said electrodes in concert.
Claim 34
Dependent Claim
25 words
A combination as set forth in claim 22, wherein each of said electrodes is adapted to include a sputtering surface comprising an electrically conductive material.
Claim 35
Dependent Claim
25 words
A combination as set forth in claim 22, wherein each of said electrodes is adapted to include a sputtering surface comprising an electrically insulating material.
Claim 36
Dependent Claim
24 words
A combination as set forth in claim 22, wherein each of said electrodes has an inwardly extending end wing at its outermost distal end.
Claim 37
Dependent Claim
23 words
A combination as set forth in claim 22, wherein each of said electrodes has an inwardly extending wing at its innermost proximal end.
Claim 38
Dependent Claim
54 words
A combination as set forth in claim 22, wherein said electrodes are coaxial and include inwardly extending wings at remote outer distal ends and further includes additional inwardly extending wings at the innermost proximal ends of said electrodes, the outer wings extending further towards the common axis of said electrodes than the inner wings.
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) | 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 |