US3616402A
Expired / Lapsed
US
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Sputtering method and apparatus
Assignee: AT&T Inc
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Filing: 1968-05-31
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Granted: 1971-10-26
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Expires: 1988-05-31
Abstract
Abstract Substrate heating by plasma electron bombardment during the sputtering of a thin film in a deposition chamber is considerably reduced by utilizing, as the sputtering target, an AC-excited array of parallel tubes formed from the film material. An oscillating electric field of large amplitude is established between adjacent ones of the tubes to entrap free electrons of the chamber gas and to thereby prevent the electrons from reaching the substrate. An auxiliary conductive member mounted adjacent and parallel to the array is biased with a DC voltage of selectable polarity for increasing the deposition rate of the sputtered material without altering the chamber pressure.
Inventors
- 👤 Henry Y Kumagai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:47
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/34; H01J37/3402; C; C23; C23C; C23C14/00; C23C14/22; C23C14/34; C23C14/35
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
20 words
Apparatus as defined in claim 1, in which the element array is disposed between the conductive member and the substrate.
Claim 2
Dependent Claim
14 words
Apparatus as defined in claim 2, in which the DC bias voltage is positive
Claim 3
Dependent Claim
19 words
Apparatus as defined in claim 1, in which the elements are arranged in a planar array about the substrate.
Claim 4
Dependent Claim
24 words
Apparatus as defined in claim 1, in which the elements are arranged in a circular array about the substrate and are disposed coaxially therewith.
Claim 5
Dependent Claim
20 words
Apparatus as defined in claim 1, further comprising means for selectively passing a succession of electrical pulses through the substrate.
Claim 6
Dependent Claim
49 words
Apparatus as defined in claim 1, in which alternate elements in the array are formed from a first metal and the remaining elements are formed from a second metal, and the apparatus further comprises means for placing the alternate elements at a different DC potential than the remaining elements.
Claim 7
Dependent Claim
22 words
Apparatus as defined in claim 1, in which each element has a centrally disposed, axially extending bore for receiving a cooling fluid.
Claim 8
Dependent Claim
24 words
Apparatus as defined in claim 1, in which the conductive member is disposed on the side of the substrate opposite from the element Array.
Claim 9
Independent Claim
162 words
A method of sputtering a conductive film on a substrate from a plurality of pairs of parallel, mutually spaced conductive elements that are arrayed symmetrically with respect to the substrate within an enclosed sputtering chamber and are made from the material to be sputtered, the steps comprising: applying an AC sputtering voltage of opposite polarities between the elements in each pair of sufficient magnitude for establishing a current density in each element to sputter material on the substrate from the instantaneously negative element of each pair at a prescribed rate for sputtering and for establishing an oscillating electric field between the elements in each pair to prevent bombardment of the substrate by any free electrons within the field; and distorting the oscillating electric field in the region between the elements by applying a DC bias voltage to a conductive plate disposed parallel and in spaced relation to the array to increase the current density in each element and raise the sputtering rate.
Claim 10
Dependent Claim
35 words
A method as set forth in claim 10 which further includes the step of imparting relative movement between the substrate and the element pairs to coat successive regions on the substrate with the sputtering material.
Claim 11
Dependent Claim
14 words
Method as defined in claim 10, in which the elements are formed from aluminum.
Claim 12
Dependent Claim
30 words
Method as defined in claim 10, in which the substrate is formed from a copper-based conductor, and each of the elements in the array is formed from a magnetic material.
Claim 13
Dependent Claim
27 words
Method as defined in claim 10, in which each element is an aluminum rod covered with a material selected from the group consisting of tantalum and titanium.
Claim 14
Dependent Claim
117 words
In an enclosed vacuum chamber for sputtering a conductive coating upon a substrate; a sputtering target comprising a plurality of parallel, mutually spaced cylindrical elements arranged in a symmetrical array about the substrate, each element being formed from the coating material to be sputtered; means for applying opposite polarities of an AC voltage to adjacent elements in the array; a conductive plate disposed parallel and in spaced relation to the array; means for applying a DC bias voltage to the conductive plate; and means for supporting the substrate for movement through the vacuum chamber along a path parallel to the plane of the array and disposed on the opposite side thereof with respect to the conductive plate.
Claim 15
Dependent Claim
17 words
Apparatus as defined in claim 15, in which adjacent pairs of the elements include a common element.
Claim 16
Dependent Claim
116 words
In an enclosed apparatus for sputtering a conductive coating onto a surface of a substrate situated within the apparatus; a sputtering target comprising a plurality of pairs of conductive elements arrayed in a configuration about the substrate, each of the elements being constructed of the coating material; means for applying between alternate elements of each pair an AC voltage of sufficient magnitude to sputter material from one element in each pair; an auxiliary conductive member disposed in coupling spaced relation to the conductive elements; means for applying a DC bias voltage to the conductive member; and means for supporting the substrate for movement passed the sputtering target to receive therefrom a coating of the sputtered material.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |