US4132612A
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: 1979-01-02
•
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
2026-10-27 04:18
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/34; H01J37/3402
Claims Analysis
Total Claims: 55
Claim 1
Independent Claim
65 words
A method of generating a glow discharge, comprising the steps of: supporting a pair of electrodes within a working gas environment; applying electrical voltage across said electrodes; and forming a magnetic field which defines, together with said electrodes, a plurality of separate traps with each electrode to contain substantially all electrons emitted from said electrodes and having sufficient energy to further ionize said working gas.
Claim 2
Independent Claim
65 words
A method of generating a glow discharge, comprising the steps of: supporting a pair of electrodes within a working gas environment; applying electrical voltage across said electrodes; and forming a magnetic field which defines, together with said electrodes, a plurality of separate traps with each electrode to contain 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
21 words
A method as set forth in claim 1, wherein said each of traps has axial symmetry about an axis of rotation.
Claim 6
Dependent Claim
18 words
A method as set forth in claim 4, wherein said axial symmetry is defined by said magnetic field.
Claim 7
Dependent Claim
17 words
A method as set forth in claim 4, wherein said axial symmetry is defined by said electrodes.
Claim 8
Dependent Claim
22 words
A method as set forth in claim 4, wherein said axial symmetry is defined by both said magnetic field and said electrodes.
Claim 9
Dependent Claim
18 words
A method as set forth in claim 1, wherein said magnetic field is formed from within said electrodes.
Claim 10
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 11
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 12
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 13
Dependent Claim
13 words
A method as set forth in claim 1, wherein said electrodes are coaxial.
Claim 14
Dependent Claim
27 words
A method as set forth in claim 1, wherein said electrodes are in a post type configuration with the glow discharge being generated externally of said electrodes.
Claim 15
Dependent Claim
23 words
A method as set forth in claim 1, wherein said electrodes are hollow and said glow discharge is generated internally of said electrodes.
Claim 16
Dependent Claim
19 words
A method as set forth in claim 1, wherein each of said electrodes defines a conical surface of revolution.
Claim 17
Dependent Claim
22 words
A method as set forth in claim 1, and further including: electrically shielding said electrodes and working gas environment against r.f. leakage.
Claim 18
Independent Claim
72 words
A method of sputtering material from a pair of target electrodes onto a substrate, comprising the steps of: disposing said electrodes within a low pressure working gas environment; forming a magnetic field which defines, together with said electrodes, a plurality of separate traps with each electrode to contain substantially all electrons emitted from said electrodes and having sufficient energy to create additional ions; and applying an r.f. voltage across said target electrodes.
Claim 19
Independent Claim
72 words
A method of sputtering material from a pair of target electrodes onto a substrate, comprising the steps of: disposing said electrodes within a low pressure working gas environment; forming a magnetic field which defines, together with said electrodes, a plurality of separate traps with each electrode to contain substantially all electrons emitted from said electrodes and having sufficient energy to create additional ions; and applying an r.f. voltage across said target electrodes.
Claim 20
Dependent Claim
24 words
A method as set forth in claim 17, and further including: maintaining said working gas environment at a pressure of 1 micron or less.
Claim 21
Dependent Claim
21 words
A method as set forth in claim 17, wherein all of said traps have axial symmetry about an axis of rotation.
Claim 22
Dependent Claim
18 words
A method as set forth in claim 19, wherein said axial symmetry is defined by said magnetic field.
Claim 23
Dependent Claim
17 words
A method as set forth in claim 19, wherein said axial symmetry is defined by said electrodes.
Claim 24
Dependent Claim
22 words
A method as set forth in claim 19, wherein said axial symmetry is defined by both said magnetic field and said electrodes.
Claim 25
Dependent Claim
18 words
A method as set forth in claim 17, wherein said magnetic field is formed from within said electrodes.
Claim 26
Dependent Claim
21 words
A method as set forth in claim 17, wherein said magnetic field is formed from a location external to said electrodes.
Claim 27
Dependent Claim
21 words
A method as set forth in claim 17, wherein said electrodes include a sputtering surface comprised of an electrically conductive material.
Claim 28
Dependent Claim
22 words
A method as set forth in claim 17, wherein said electrode assembly includes a sputtering surface comprised of an electrically insulating material.
Claim 29
Dependent Claim
13 words
A method as set forth in claim 17, wherein said electrodes are coaxial.
Claim 30
Dependent Claim
27 words
A method as set forth in claim 17, wherein said electrodes are in a post type configuration with the glow discharge being generated externally of said electrodes.
Claim 31
Dependent Claim
23 words
A method as set forth in claim 17, wherein said electrodes are hollow and said glow discharge is generated internally of said electrodes.
Claim 32
Dependent Claim
19 words
A method as set forth in claim 17, wherein each of said electrodes defines a conical surface of revolution.
Claim 33
Dependent Claim
22 words
A method as set forth in claim 17, and further including: electrically shielding said electrodes and working gas environment against r.f. leakage.
Claim 34
Dependent Claim
71 words
In an r.f. glow discharge system, the combination comprising: a pair of shaped electrodes, said electrodes being appropriately shaped and located to complement a magnetic field in providing electron trap boundaries; and means for forming a magnetic field which defines, in cooperation with said shaped electrodes, a plurality of separate traps with each electrode for containing substantially all electrons emitted from said electrodes and having sufficient energy to create additional ions.
Claim 35
Dependent Claim
71 words
In an r.f. glow discharge system, the combination comprising: a pair of shaped electrodes, said electrodes being appropriately shaped and located to complement a magnetic field in providing electron trap boundaries; and means for forming a magnetic field which defines, in cooperation with said shaped electrodes, a plurality of separate traps with each electrode for containing substantially all electrons emitted from said electrodes and having sufficient energy to create additional ions.
Claim 36
Dependent Claim
25 words
A combination as set forth in claim 32, wherein said electrodes are disposed in a gaseous environment at a pressure of one micron or less.
Claim 37
Dependent Claim
21 words
A combination as set forth in claim 32, wherein each of said traps has axial symmetry about an axis of rotation.
Claim 38
Dependent Claim
24 words
A combination as set forth in claim 1, and further including: means for electrically shielding said electrodes and said glow discharge against r.f. leakage.
Claim 39
Dependent Claim
21 words
A combination as set forth in claim 32, wherein said means for forming a magnetic field is located within said electrodes.
Claim 40
Dependent Claim
21 words
A combination as set forth in claim 32, wherein said means for forming said magnetic field is external of said electrodes.
Claim 41
Dependent Claim
27 words
A combination as set forth in claim 32, wherein said electrodes are in a post type configuration with the glow discharge being generated externally of said electrodes.
Claim 42
Dependent Claim
23 words
A combination as set forth in claim 32, wherein said electrodes are hollow and said glow discharge is generated internally of said electrodes.
Claim 43
Dependent Claim
25 words
A combination as set forth in claim 32, wherein each of said electrodes is adapted to include a sputtering surface comprising an electrically conductive material.
Claim 44
Dependent Claim
25 words
A combination as set forth in claim 32, wherein each of said electrodes is adapted to include a sputtering surface comprising an electrically insulating material.
Claim 45
Dependent Claim
103 words
Glow discharge apparatus, comprising: a pair of shaped electrodes, said electrodes being appropriately shaped and located to complement a magnetic field in providing electron trap boundaries; 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, in cooperation with said shaped electrodes a plurality of separate completely closed traps with each electrode for containing substantially all electrons emitted from said electrodes and having sufficient energy to further ionize said working gas.
Claim 46
Dependent Claim
103 words
Glow discharge apparatus, comprising: a pair of shaped electrodes, said electrodes being appropriately shaped and located to complement a magnetic field in providing electron trap boundaries; 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, in cooperation with said shaped electrodes a plurality of separate completely closed traps with each electrode for containing substantially all electrons emitted from said electrodes and having sufficient energy to further ionize said working gas.
Claim 47
Dependent Claim
20 words
Apparatus as set forth in claim 42, wherein said working gas is at a pressure of 1 micron or less.
Claim 48
Dependent Claim
21 words
Apparatus as set forth in claim 42, wherein said electrical voltage applied across said pair of electrodes is an r.f. voltage.
Claim 49
Dependent Claim
20 words
Apparatus as set forth in claim 42, wherein each of said traps has axial symmetry about an axis of rotation.
Claim 50
Dependent Claim
20 words
Apparatus as set forth in claim 42, wherein said mounting means supports said electrodes in coaxial relationship to each other.
Claim 51
Dependent Claim
25 words
Apparatus as set forth in claim 42, wherein said electrodes are in a post-type configuration with said glow discharge being generated externally of said electrodes.
Claim 52
Dependent Claim
22 words
Apparatus as set forth in claim 42, wherein said electrodes are hollow and said glow discharge is generated internally of said electrodes.
Claim 53
Dependent Claim
18 words
Apparatus as set forth in claim 42, wherein each of said electrodes defines a conical surface of revolution.
Claim 54
Dependent Claim
17 words
Apparatus as set forth in claim 42, wherein said magnetic field means is located within said electrodes.
Claim 55
Dependent Claim
18 words
Apparatus as set forth in claim 42, wherein said magnetic field means is located externally of said electrodes.
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) | 1982-01-01 | 1982-07-03 | 1983-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-01 | 1986-07-03 | 1987-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-01 | 1990-07-03 | 1991-01-02 | $7700.00 | Window Closed / Lapsed |