US4060470A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sputtering apparatus and method
Assignee: Individual
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Filing: 1975-12-19
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Granted: 1977-11-29
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Expires: 1995-12-19
Abstract
Abstract The sputtering apparatus includes a concentric anode and cathode electrode and a magnetic structure for producing a magnetic field crossed with the electric field (magnetron type discharge) over the cathode region to be sputtered for enhancing the sputtering operation. The magnetic structure includes field shaping means, such as shunts or bucking magnets, to limit the cathode dark space substantially to the effective sputter surface of the cathode. A ground shield surrounding the cathode, but not extending into the dark space, is utilized to contribute to the effect produced by the magnetic field, and means are provided for cooling the anode and cathode. In the case of sputtering ferromagnetic material, a ferromagnetic sputter cathode has its thickness dimensioned so as to be magnetically saturated by the applied magnetic field in a region of relatively low sputter erosion and to be thicker in regions of more intense sputter erosion.
Inventors
- 👤 Peter J. Clarke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:46
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/34; H01J37/3411; H01J37/3414; H01J37/3423; H01J37/3402; H01J37/3405; H01J37/3408; H01J37/3426; H01J37/345; H01J37/3452
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
213 words
Glow discharge sputtering apparatus for coating a work piece including: anode and cathode electrode means for operation at independent operating electrical potentials to establish in use a main electric field intercepted by said cathode means; said cathode electrode means adapted to contain a main portion made of a material to be sputtered from said cathode means onto the work piece; magnet means including a main magnetic circuit for producing a main magnetic field passing out of and looping back into said main cathode portion and a stray magnetic field not intercepted by said main cathode portion and said main magnetic field being crossed with said electric field over said main cathode portion; means for applying an operating electrical potential between said anode and cathode means for establishing in operation a main magnetically enhanced glow discharge over said main cathode portion for bombarding said main portion of said cathode means with positive ions to produce sputtering of said cathode material onto the work piece; and said magnetic circuit including stray glow discharge suppression means for shaping said stray magnetic field lines in a stray glow discharge region which is otherwise susceptible of supporting a stray glow discharge therein in order to reduce the intensity of said stray glow discharge and stray sputtering generated thereby.
Claim 2
Dependent Claim
213 words
Glow discharge sputtering apparatus for coating a work piece including: anode and cathode electrode means for operation at independent operating electrical potentials to establish in use a main electric field intercepted by said cathode means; said cathode electrode means adapted to contain a main portion made of a material to be sputtered from said cathode means onto the work piece; magnet means including a main magnetic circuit for producing a main magnetic field passing out of and looping back into said main cathode portion and a stray magnetic field not intercepted by said main cathode portion and said main magnetic field being crossed with said electric field over said main cathode portion; means for applying an operating electrical potential between said anode and cathode means for establishing in operation a main magnetically enhanced glow discharge over said main cathode portion for bombarding said main portion of said cathode means with positive ions to produce sputtering of said cathode material onto the work piece; and said magnetic circuit including stray glow discharge suppression means for shaping said stray magnetic field lines in a stray glow discharge region which is otherwise susceptible of supporting a stray glow discharge therein in order to reduce the intensity of said stray glow discharge and stray sputtering generated thereby.
Claim 3
Dependent Claim
54 words
The apparatus of claim 1 wherein said stray glow discharge suppression means includes means for shaping the stray magnetic field to be generally parallel to the electric field lines in said stray glow discharge region for suppressing the intensity of said stray glow discharge and for decreasing the resultant stray cathode sputtering generated therefrom.
Claim 4
Dependent Claim
51 words
The apparatus of claim 1 wherein said stray glow discharge suppression means includes means for shaping the stray magnetic field to be of substantially of reduced intensity in said stray glow discharge region for suppressing the intensity of said stray glow discharge and for decreasing the resultant cathode sputtering generated therefrom.
Claim 5
Dependent Claim
78 words
The apparatus of claim 1 wherein said stray glow discharge suppression means includes an auxiliary source of magnetomotive force for producing an auxiliary magnetic field of a polarity for bucking said stray magnetic field of said main magnetic field in said region of stray glow discharge for shaping the magnetic field in said region of said stray glow discharge for suppressing the intensity of said stray glow discharge and for decreasing the resultant stray cathode sputtering generated therefrom.
Claim 6
Dependent Claim
76 words
The apparatus of claim 4 wherein said anode electrode means includes ground shield means disposed in electrically insulative relation to said cathode means for operation in use at an electrical ground potential positive relative to the operating electrical potential of said cathode means; said ground shield means being spaced from and being adjacent to said cathode means to establish a gap therebetween into which said stray magnetic field extends to define said stray glow discharge region.
Claim 7
Dependent Claim
65 words
The apparatus of claim 1 wherein said stray glow discharge suppression means includes a magnetic shunt means associated with said magnetic circuit means for shunting a portion of the stray magnetic field from and for shaping the stray magnetic field in said region of stray glow discharge for suppressing the intensity of said glow discharge and for decreasing the resultant stray cathode sputtering generated therefrom.
Claim 8
Dependent Claim
97 words
The apparatus of claim 1 wherein, said sputter cathode means is adopted to be made of a ferromagnetic material for bombardment with positive ions generated in the crossed field region over said sputter cathode means for sputtering ferromagnetic material from said sputter cathode means onto a workpiece to be coated; and said sputter cathode means including a magnetically saturable first portion of substantially less thickness than a second portion of said cathode so that the magnetic field lines pass through said saturable first portion of said cathode and loop back into said second portion of said cathode.
Claim 9
Dependent Claim
48 words
The apparatus of claim 7 wherein said first portion of said cathode comprises at least a portion of a hollow cylindrical structure having a length substantially greater than its wall thickness, and wherein said second portion of said cathode comprises at least a portion of an annular disc.
Claim 10
Dependent Claim
132 words
In a glow discharge sputtering method for coating a work piece, the steps of: producing crossed magnetic and electric fields over the main surface of a cathode electrode made of a material to be sputtered onto the work piece, such produced magnetic field having a stray magnetic field component disposed over portions of the cathode electrode structure from which sputtering is to be suppressed; suppressing the stray sputtering of the cathode electrode structure by shaping the stray magnetic field in the region of the stray glow discharge region so as to substantially reduce the intensity of the stray magnetic field component at right angles to the electric field component in the region of the stray glow discharge, whereby such stray glow discharge is substantially suppressed thereby suppressing undesired cathode sputtering resulting therefrom.
Claim 11
Dependent Claim
132 words
In a glow discharge sputtering method for coating a work piece, the steps of: producing crossed magnetic and electric fields over the main surface of a cathode electrode made of a material to be sputtered onto the work piece, such produced magnetic field having a stray magnetic field component disposed over portions of the cathode electrode structure from which sputtering is to be suppressed; suppressing the stray sputtering of the cathode electrode structure by shaping the stray magnetic field in the region of the stray glow discharge region so as to substantially reduce the intensity of the stray magnetic field component at right angles to the electric field component in the region of the stray glow discharge, whereby such stray glow discharge is substantially suppressed thereby suppressing undesired cathode sputtering resulting therefrom.
Claim 12
Dependent Claim
54 words
The method of claim 9 wherein the step of shaping the stray magnetic field so as to substantially decrease components of stray magnetic field at right angles to the electric field includes the step of shaping the stray magnetic field to be generally parallel to the electric field in the stray glow discharge region.
Claim 13
Dependent Claim
43 words
The method of claim 9 wherein the step of suppressing the stray glow discharge includes the step of reducing the intensity of the stray magnetic field in the region of the stray glow discharge for suppressing the intensity of the stray glow discharge.
Claim 14
Dependent Claim
76 words
The method of claim 9 wherein the step of suppressing the stray glow discharge includes the step of generating a second magnetic field in the region of the stray magnetic field, such second magnetic field being polarized in opposition to the first field for shaping the magnetic field in the stray glow discharge region to reduce the intensity of the resultant component of magnetic field orthogonal to the electric field in the stray glow discharge region.
Claim 15
Dependent Claim
70 words
The method of claim 9 wherein the step of suppressing the stray glow discharge includes the step of shunting a portion of the stray field in the region of the stray glow discharge so as to reduce the intensity of the stray magnetic field component at right angles to the electric field components in the region of the stray glow discharge, whereby the stray glow discharge is suppressed in use.
Claim 16
Dependent Claim
123 words
Glow discharge sputtering apparatus for coating a workpiece comprising, a cathode adapted to contain a material to be sputtered, an anode disposed adjacent said said cathode for producing an electric field over a surface of said cathode which is to be sputtered, a first magnetic structure producing a first magnetic field intercepting said cathode and having a substantial component directed orthogonally to the electric field produced between said anode and cathode over the surface of said cathode to be sputtered, second magnetic field means associated with an end region of the first magnetic structure for compressing the end region of the first magnetic field to effectively limit sputtering to the intermediate main area of said cathode, whereby stray sputtering is reduced in use.
Claim 17
Dependent Claim
123 words
Glow discharge sputtering apparatus for coating a workpiece comprising, a cathode adapted to contain a material to be sputtered, an anode disposed adjacent said said cathode for producing an electric field over a surface of said cathode which is to be sputtered, a first magnetic structure producing a first magnetic field intercepting said cathode and having a substantial component directed orthogonally to the electric field produced between said anode and cathode over the surface of said cathode to be sputtered, second magnetic field means associated with an end region of the first magnetic structure for compressing the end region of the first magnetic field to effectively limit sputtering to the intermediate main area of said cathode, whereby stray sputtering is reduced in use.
Claim 18
Dependent Claim
24 words
Glow discharge sputtering apparatus according to claim 14 wherein a second magnetic structure produces said second magnetic field, and said structures are oppositely polarized.
Claim 19
Dependent Claim
117 words
Glow discharge sputtering apparatus according to claim 14 including a plate of magnetic material and constituting a first pole piece, means insulating said anode from said plate with said cathode surrounding said anode and electrically connected to said plate, said first magnetic structure being carried by said plate and surrounding said cathode, said first magnetic structure being polarized in a direction normal to said plate, a second pole piece surrounding said cathode and overlying said first magnetic structure, a second magnetic structure producing said second field, the last said structure overlying said second pole piece and polarized in a direction opposite to said first magnetic structure and a third magnetic pole piece overlying said second magnetic structure.
Claim 20
Dependent Claim
58 words
Glow discharge sputtering apparatus according to claim 16 wherein said apparatus is disposed within an evacuable chamber and means are provided for the application of a potential difference between said cathode and anode to produce a dark space over the surface of said cathode, and wherein a shield encloses said magnetic structures and extends inwardly toward said cathode.
Claim 21
Dependent Claim
38 words
Glow discharge sputtering apparatus according to claim 16 including a fluid cooled jacket surrounding said cathode, said cathode expandable by reason of the heat produced during operation of said apparatus to contact said jacket and dissipate heat thereto.
Claim 22
Dependent Claim
55 words
Glow discharge sputtering apparatus according to claim 18 including a hollow anode support extending in insulating relationship through said plate of magnetic material, inlet and outlet liquid conduits communicating with said hollow anode support, inlet and outlet conduits communicating with said cooling jacket and means for circulating a liquid through said jacket and anode support.
Claim 23
Dependent Claim
22 words
Glow discharge sputtering apparatus according to claim 16 wherein said first and second magnetic structures each comprise a plurality of permanent magnets.
Claim 24
Dependent Claim
31 words
Glow discharge sputtering apparatus according to claim 20 wherein said third pole piece includes a peripheral shield magnetically coupled thereto and extending toward and magnetically coupled to said first pole piece.
Claim 25
Dependent Claim
46 words
Glow discharge sputtering apparatus according to claim 21 including a ground shield overlying said third pole piece and insulated therefrom, said shield having an inner edge spaced from said cathode and a peripheral portion spaced from said magnetic structures and electrically connected to said base plate.
Claim 26
Dependent Claim
38 words
Glow discharge sputtering apparatus according to claim 22 wherein said ground shield includes a ring disposed about the inner edge thereof, said ring having a tapered surface terminating at its inner edge in spaced relationship to said cathode.
Claim 27
Dependent Claim
179 words
Glow discharge sputtering apparatus according to claim 16 including a base plate, a plate of magnetic material overlying said base plate and insulated therefrom, an anode support carried by said base plate and extending in insulating relationship through said plate of magnetic material, said anode being secured to said support with said cathode surrounding said anode and electrically connected to said plate of magnetic material, a plurality of magnets surrounding said cathode and polarized in a direction substantially normal to said plate, said magnets being carried by said plate of magnetic material, said plate of magnetic material forming a first pole piece, a second pole piece overlying said magnets, and producing a magnetic field extending in a curved path through said cathode to said first pole piece, a second magnetic structure overlying said second pole piece and a third pole piece overlying said second set of magnets, said second magnetic structure being polarized in a direction opposite to the polarization of said first magnetic structure and functioning to compress the field thereof substantially to the confines of said cathode.
Claim 28
Dependent Claim
58 words
Glow discharge sputtering apparatus according to claim 24 wherein said anode is insulated from said base plate, said cathode includes means for applying a potential negative with respect to said base plate and said anode includes means for applying a potential positive with respect to said base plate whereby said ion and electric currents are made substantially equal.
Claim 29
Dependent Claim
27 words
Glow discharge sputtering apparatus according to claim 14 including means for polarizing said cathode negative with respect to ground and said anode positive with respect to ground.
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) | 1980-11-28 | 1981-05-30 | 1981-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-28 | 1985-05-30 | 1985-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-28 | 1989-05-30 | 1989-11-29 | $7700.00 | Window Closed / Lapsed |