Patent US2515481A successfully refreshed from Google Patents.
Patent EP0475838A2 successfully refreshed from Google Patents.
EP0475838A2
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EP
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Superconducting device having a reduced thickness of oxide superconducting layer and method for manufacturing the same
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1991-09-10
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Granted: —
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Expires: 2011-09-10
Abstract
Abstract A superconducting device comprises first and second oxide superconducing regions of a relatively thick thickness formed directly on a principal surface of a substrate separately from each other, and a third oxide superconducting region of an extremely thin thickness formed directly on the principal surface of the substrate so as to bridge the first and second oxide superconducting regions. A barrier layer and a diffusion source layer is formed on the third oxide superconducting region, and an isolation region is formed to cover an upper portion or both side surfaces of the diffusion source layer. The first, second and third oxide superconducting regions and the isolation region are formed of the same oxide superconductor material, and the isolation region is diffused with a material of the diffusion source layer, so that the isolation region does not show superconductivity. Therefore, a superconducting current can flow between the first and second oxide superconducting regions through only the third oxide superconducting region. For formation of the superconducting device, a first oxide superconductor thin film having a very thin thickness is formed on the principal surface of the substrate, and a barrier layer and a diffusion source layer are formed on a portion of the first oxide superconductor thin film. A second oxide superconductor thin film is grown on an exposed surface of the first oxide superconductor thin film until the two layers are embedded in the second oxide superconductor thin film, so that a material of the diffusion source layer is diffused into the second oxide superconductor thin film on an upper portion or both side surfaces of the diffusion source layer.
Inventors
- 👤 Takao Nakamura
- 👤 Hiroshi Inada
- 👤 Michitomo Iiyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 04:37
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/20; H10N60/205; H10N60/207; H10N60/01; H10N60/0912; H10N60/0941; H10N60/10; H10N60/12; H10N60/124; Y; Y10; Y10S; Y10S505/00; Y10S505/70; Y10S505/701; Y10S505/702; Y10S505/725; Y10S505/728
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
205 words
A superconducting device comprising a substrate having a principal surface, first and second oxide superconducting regions of a relatively thick thickness formed directly on the principal surface of the substrate separately from each other, and a third oxide superconducting region of an extremely thin thickness formed directly on the principal surface of the substrate between the first and second oxide superconducting regions so as to bridge the first and second oxide superconducting regions, a barrier layer of a non-superconductor material formed directly on the third oxide superconducting region, a diffusion source layer of a non-superconductor material formed on the barrier layer, and an isolation region formed to cover an upper portion or both side surfaces of the diffusion source layer, the first, second and third oxide superconducting regions and the isolation region being formed of the same oxide superconductor material, the isolation region being diffused with the same material as at least one material contained in the diffusion source layer, so that when the first and second oxide superconducting regions are brought into a superconducting condition, the isolation region does not show superconductivity, and therefore, a superconducting current can flow between the first and second oxide superconducting regions through only the third oxide superconducting region.
Claim 2
Dependent Claim
35 words
A superconducting device claimed in Claim 1 wherein at least the first and second oxide superconducting regions and the isolation region are formed of a single oxide superconductor thin film having a substantially planar surface.
Claim 3
Dependent Claim
41 words
A superconducting device claimed in Claim 2 wherein the oxide superconductor material is selected from the group consisting of a Y-Ba-Cu-O type compound oxide superconductor material, a Bi-Sr-Ca-Cu-O type compound oxide superconductor material, and a Tl-Ba-Ca-Cu-O type compound oxide superconductor material.
Claim 4
Dependent Claim
26 words
A superconducting device claimed in Claim 3 wherein the first, second and third oxide superconducting regions are formed of single c -axis orientated single crystal film.
Claim 5
Dependent Claim
36 words
A superconducting device claimed in Claim 4 wherein the diffusion source layer is formed of a material selected from the group consisting of silicon and silicide, and the isolation region is diffused with at least silicon.
Claim 6
Dependent Claim
31 words
A superconducting device claimed in Claim 5 wherein the barrier layer is formed of a material stable to the oxide superconductor material of the first, second and third oxide superconducting regions.
Claim 7
Dependent Claim
38 words
A superconducting devide claimed in Claim 5 wherein the substrate is formed of a material selected from the group consisting of a MgO (100) substrate, a SrTiO₃ (100) substrate and a CdNdAlO₄ (001) substrate, and a semiconductor substrate.
Claim 8
Dependent Claim
43 words
A superconducting device claimed in Claim 5 wherein the substrate is formed of a semiconducting material substrate and a principal surface of the semiconducting material substrate is coated with an insulating material layer which is formed of a MgAlO₄layer and a BaTiO₃ layer.
Claim 9
Dependent Claim
58 words
A superconducting device claimed in Claim 1 wherein the isolation region is formed to cover at least the upper portion of the diffusion source layer and the third oxide superconducting region has a thickness of not greater than 10 nm and form a weak link of a Josephson junction, so that the superconducting device constitutes a Josephson device.
Claim 10
Dependent Claim
31 words
A superconducting device claimed in Claim 9 wherein the barrier layer is formed of a metal stable to the oxide superconductor material of the first, second and third oxide superconducting regions.
Claim 11
Dependent Claim
20 words
A superconducting device claimed in Claim 10 wherein the metal is selected from the group consisting of Au and Pt.
Claim 12
Dependent Claim
49 words
A superconducting device claimed in Claim 1 further including a first electrode formed on the first oxide superconducting region and a second electrode formed on the second oxide superconducting region, so that a superconducting current can flow between the first and second electrodes through the third oxide superconducting region.
Claim 13
Dependent Claim
73 words
A superconducting device claimed in Claim 12 wherein the diffusion source layer is formed of a conducting material and exposed so as to function as a gate electrode, and the isolation region is formed of an isolating material, so that the superconducting device constitutes a super-FET, and the superconducting current flowing between the first and second electrodes through the third oxide superconducting region is controlled by a voltage applied to the gate electrode.
Claim 14
Dependent Claim
30 words
A superconducting device claimed in Claim 13 wherein each of the first and second electrodes and the gate electrode is formed of a superconductor material or a normal conductor material.
Claim 15
Dependent Claim
46 words
A superconducting device claimed in Claim 13 wherein the isolation region is formed of an insulating material which does not form a large density of energy levels between the oxide superconductor material of the third oxide superconducting region and the insulating material of the isolation region.
Claim 16
Dependent Claim
38 words
A superconducting device claimed in Claim 15 wherein the third oxide superconducting region has a thickness of about 5 nm and the isolation region is formed of MgO and has a thickness of not less than 10 nanometers.
Claim 17
Independent Claim
157 words
A method of manufaturing a superconducting device, comprising the step of preparing a substrate having a planar principal thereof, forming a first oxide superconductor thin film having a very thin thickness on the principal surface of the substrate, forming on a portion of the first oxide superconductor thin film a stacked structure including a barrier layer formed directly on the first oxide superconductor thin film and a diffusion source layer formed on the barrier layer, and growing a second oxide superconductor thin film on an exposed surface of the first oxide superconductor thin film until the stacked structure is embedded in the second oxide superconductor thin film, so that at least one material contained in the diffusion source layer is diffused into an region of the second oxide superconductor thin film surrounding the diffusion source layer, and the diffused region does not show superconductivity when a non-diffused region of the second oxide superconductor thin film shows superconductivity.
Claim 18
Dependent Claim
61 words
A method claimed in Claim 17 wherein after formation of the second oxide superconductor thin film, a resist layer is coated on the second oxide superconductor thin film so as to have a flat upper surface, and the resist layer and the second oxide superconductor thin film are etched back until the oxide superconductor thin film has the planar upper surface.
Claim 19
Dependent Claim
24 words
A method claimed in Claim 18 wherein the the second oxide superconductor thin film is etched back until the diffusion source layer is exposed.
References Cited (Backward Citations)
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