EP0545816A2
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EP
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Method for manufacturing a Josephson junction device having weak link of artificial grain boundary
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1992-12-02
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Granted: —
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Expires: 2012-12-02
Abstract
Abstract A Josephson junction device comprises a single crystalline substrate (5) including a principal surface having a first and a second region of which at least lattice distance of exposed lattices are slightly different from each other and an oxide superconductor thin film (11,12) formed on the principal surface of the substrate (5). The oxide superconductor thin film includes a first (11) and a second (12) portion respectively positioned on the first and the second regions of the substrate, which are constituted of single crystals of the oxide superconductor, lattices of the one shifts at an angle of 45° to that of the other, and a grain boundary (3) between said two portions, which constitutes a weak link of the Josephson junction.
Inventors
- 👤 So Tanaka
- 👤 Hiroshi Inada
- 👤 Michitomo Iiyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 04:47
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0912; H10N60/0941; Y; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/729; Y10S505/80; Y10S505/815; Y10S505/818; Y10S505/82; Y10S505/825; Y10S505/917; Y10S505/922
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
110 words
A Josephson junction device comprising a single crystalline substrate including a principal surface having a first and a second regions of which at least lattice distance of exposed lattices are slightly different from each other, and an oxide superconductor thin film formed on the principal surface of the substrate, which includes a first and a second portions respectively positioned on the first and the second regions of the substrate, which are constituted of single crystals of the oxide superconductor, lattices of the one shifts at angle of 45° to that of the other and a grain boundary between said two portions, which constitutes a weak link of the Josephson junction.
Claim 2
Dependent Claim
23 words
A Josephson junction device claimed in Claim 1 wherein the oxide superconductor thin film is a c -axis orientated oxide superconductor thin film.
Claim 3
Dependent Claim
26 words
A Josephson junction device claimed in Claim 1 wherein a step is formed on the principal surface of the substrate between the first and second regions.
Claim 4
Dependent Claim
15 words
A Josephson junction device claimed in Claim 1 wherein the substrate is formed of MgO.
Claim 5
Dependent Claim
33 words
A Josephson junction device claimed in Claim 4 the Josephson junction device further comprises SrTiO₃ buffer layer which constitutes one of the first and second regions of the principal surface of the substrate.
Claim 6
Dependent Claim
37 words
A Josephson junction device claimed in Claim 1 wherein the oxide superconductor thin film is formed of a high-T c , (high critical temperature) oxide superconductor, particularly, formed of a high-T c copper-oxide type compound oxide superconductor..
Claim 7
Dependent Claim
49 words
A Josephson junction device claimed in Claim 6 wherein the oxide superconductor thin film is formed of an oxide superconductor material 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 8
Independent Claim
138 words
A method for manufacturing a Josephson junction device comprising the steps of wet-etching at least a portion of a principal surface of the single crystalline substrate so that the principal surface includes a first and a second regions of which at least lattice distance of exposed lattices are slightly different from each other and forming an oxide superconductor thin film on the first and second regions of the principal surface so that the oxide superconductor thin film includes a first and a second portions respectively positioned on the first and the second regions of the substrate, which are constituted of single crystals of the oxide superconductor, lattices of the one shifts at angle of 45 ° to that of the other, and a grain boundary between said two portions, which constitutes a weak link of the Josephson junction.
Claim 9
Dependent Claim
139 words
A method claimed in Claim 8 wherein the method comprises steps of wet-etching a portion of the principal surface of the substrate so as to form a step, a first and a second regions of which lattice distance of exposed lattices are slightly different from each other at the both sides of the step and forming an oxide superconductor thin film on the first and second regions of the principal surface so that the oxide superconductor thin film includes a first and a second portions respectively positioned on the first and the second regions of the substrate, which are constituted of single crystals of the oxide superconductor, lattices of the one shifts at angle of 45 ° to that of the other, and a grain boundary between said two portions, which constitutes a weak link of the Josephson junction.
Claim 10
Dependent Claim
150 words
A method claimed in Claim 8 wherein the method comprises steps of wet-etching the principal surface of the substrate, dry-etching a portion of the wet-etched principal surface in order to remove a surface of the portion so as to forn a first and a second regions on the principal surface of the substrate, of which lattice distance of exposed lattices are slightly different from each other and forming an oxide superconductor thin film on the first and second regions of the principal surface so that the oxide superconductor thin film includes a first and a second portions respectively positioned on the first and the second regions of the substrate, which are constituted of single crystals of the oxide superconductor, lattices of the one shifts at angle of 45° to that of the other, and a grain boundary between said two portions, which constitutes a weak link of the Josephson junction.
Claim 11
Dependent Claim
179 words
A method claimed in Claim 8 wherein the method comprises the steps of etching a portion of a principal surface of MgO single crystal substrate so as to form a step, forming a layer of material other than MgO which can be a base of an oxide superconductor thin film only at a portion below the step so that the principal surface is substantially planarized, wet-etching the principal surface of the substrate so as to form a first and a second regions of which lattice distance of exposed lattices are slightly different from each other and forming an oxide superconductor thin film on the first and second regions of the principal surface so that the oxide superconductor thin film includes a first and a second portions respectively positioned on the first and the second regions of the substrate, which are constituted of single crystals of the oxide superconductor, lattices of the one shifts at angle of 45° to that of the other, and a grain boundary between said two portions, which constitutes a weak link of the Josephson junction.
References Cited (Backward Citations)
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