EP0484251A2
Expired / Lapsed
EP
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Superconducting device having an extremely short superconducting channel formed of extremely thin oxide superconductor film and method for manufacturing the same
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1991-10-31
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Granted: —
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Expires: 2011-10-31
Abstract
Abstract A superconducting device comprises a superconducting channel constituted in an oxide superconductor thin film deposited on a deposition surface of a substrate. A source electrode and a drain electrode are formed on the oxide superconductor thin film at opposite ends of the superconducting channel, so that a superconducting current can flow through the superconducting channel between the superconductor source electrode and the superconductor drain electrode. A gate electrode is formed through a gate insulator layer on the superconducting channel so as to control the superconducting current flowing through the superconducting channel. The gate electrode is in the form of a thin film and stands upright to the gate insulator layer.
Inventors
- 👤 Takao Nakamura
- 👤 Hiroshi Inada
- 👤 Michitomo Iiyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 20:00
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/20; H10N60/205; H10N60/207; Y; Y10; Y10S; Y10S505/00; Y10S505/70; Y10S505/701
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
108 words
A superconducting device comprising a substrate, a superconducting channel constituted in an oxide superconductor thin film deposited on a deposition surface of sais substrate, a source electrode and a drain electrode formed on the oxide superconductor thin film at opposite ends of said superconducting channel, so that a superconducting current can flow through said superconducting channel between said source electrode and said drain electrode, and a gate electrode formed through a gate insulator layer on said superconducting channel so as to control the superconducting current flowing through said superconducting channel, said gate electrode being in the form of a thin film standing upright to said gate insulator layer.
Claim 2
Dependent Claim
23 words
A superconducting device claimed in Claim 1 wherein said gate electrode in the form of a thin film is located above said substrate.
Claim 3
Dependent Claim
38 words
A superconducting device claimed in Claim 2 wherein said gate electrode in the form of a thin film has a thickness of not greater than 100nm in a direction of an electric current flowing through said superconducting channel.
Claim 4
Dependent Claim
84 words
A superconducting device claimed in Claim 1 wherein a protection layer is formed on said gate insulator layer to have an end surface above said superconducting channel, said end surface of said protection layer being substantially perpendicular to said substrate, and said gate electrode in the form of a thin film is formed of a conducting thin film which is deposited on said end surface of said protection layer and which is at only its lower end in contact with said gate insulator layer.
Claim 5
Dependent Claim
66 words
A superconducting device claimed in Claim 4 wherein said oxide superconductor thin film of said superconducting channel is formed of a c -axis oriented oxide superconductor crystal layer having a thickness of not greater than five nanometers, and each of said source electrode, said gate electrode and said drain electrode is constituted of a superconducting electrode formed of an α -axis oriented oxide superconductor crystal layer.
Claim 6
Dependent Claim
100 words
A superconducting device claimed in Claim 2 wherein said superconducting channel has a thickness of not greater than five nanometers, and said oxide superconductor thin film of said superconducting channel has an upper planar surface, wherein said gate insulator layer is deposited on said upper planar surface of said oxide superconductor thin film, and an insulating protection layer is formed on the gate insulator layer and having an end surface angled to said gate insulator layer, wherein said gate electrode is formed of a thin film of a normal conductor deposited on said end surface of said insulating protection layer.
Claim 7
Dependent Claim
107 words
A superconducting device claimed in Claim 2 wherein said source electrode and said drain electrode are constitued of a superconducting source electrode and a superconducting drain electrode, respectively, which are located on the oxide superconductor thin film of the superconducting channel through an extremely thin insulator layer, and wherein said superconducting source electrode and said superconducting drain electrode are in electrical connection with said oxide superconductor thin film of said superconducting channel because of flocculation generated in said extremely thin insulator layer sandwiched between said oxide superconductor thin film of said superconducting channel and each of said oxide superconducting source electrode and said oxide superconducting drain electrode.
Claim 8
Dependent Claim
28 words
A superconducting device claimed in Claim 7 wherein said extremely thin insulator layer is formed of a MgO film having a thickness of not greater than ten nanometers.
Claim 9
Dependent Claim
63 words
A superconducting device claimed in Claim 8 wherein said oxide superconductor thin film of said superconducting channel is formed of a c -axis oriented oxide superconductor crystal layer having a thickness of not greater than five nanometers, and each of said superconducting source electrode, said gate electrode and said superconducting drain electrode is formed of an α -axis oriented oxide superconductor crystal layer.
Claim 10
Dependent Claim
21 words
A superconducting device claimed in Claim wherein the first to fourth superconducting layers are formed of a high-Tc oxide superconductor material.
Claim 11
Dependent Claim
23 words
A superconducting device claimed in Claim wherein the first to fourth superconducting layers are formed of a high-Tc copper-oxide type oxide superconductor material.
Claim 12
Dependent Claim
48 words
A superconducting device claimed in Claim 10 wherein the first to fourth superconducting layers are formed of the same 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 13
Dependent Claim
38 words
A superconducting device claimed in Claim 1 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 14
Dependent Claim
98 words
A superconducting device comprising a substrate having a gate electrode embedded in said substrate, a gate insulator deposited on a deposition surface of said substrate, a superconducting channel constitued in an oxide superconductor thin film deposited on said gate insulator, a source electrode and a drain electrode formed on said oxide superconductor thin film at opposite ends of said superconducting channel, so that a superconducting current can flow through said superconducting channel between said source electrode and said drain electrode, said gate electrode being in the form of a thin film standing upright to said gate insulator layer.
Claim 15
Dependent Claim
38 words
A superconducting device claimed in Claim 14 wherein said gate electrode in the form of a thin film has a thickness of not greater than 100nm in a direction of an electric current flowing through said superconducting channel.
Claim 16
Dependent Claim
66 words
A superconducting device claimed in Claim 14 wherein said oxide superconductor thin film of said superconducting channel is formed of a c -axis oriented oxide superconductor crystal layer having a thickness of not greater than five nanometers, and each of said source electrode, said gate electrode and said drain electrode is constituted of a superconducting electrode formed of an α -axis oriented oxide superconductor crystal layer.
Claim 17
Independent Claim
114 words
A method for manufacturing a superconducting device, including the step of forming on a substrate an oxide superconductor thin film having a planar upper surface, depositing a gate insulator layer on said planar upper surface of said oxide superconductor thin film, forming on said gate insulator layer at least one protection layer having an end surface positioned above said superconducting region, and depositing on said end surface of said at least one insulating protection layer a thin film of a conducting material so that said deposited thin film of a conducting material forms a gate electrode in the form of a thin film having a lower end in contact with said gate insulator layer.
Claim 18
Independent Claim
132 words
A method for manufacturing a superconducting device, including the steps of depositing an oxide superconductor thin film on a substrate having a stepped portion, selectively removing the deposited oxide superconductor thin film from the substrate so as to leave the deposited oxide superconductor thin film on only the side surface of said stepped portion, filling a material into a recess formed by said stepped portion so that a planar upper surface is formed on said substrate and an upper end of the remaining oxide superconductor thin film deposited on said stepped portion is exposed on said planar upper surface, forming a gate insulator layer on said planar upper surface, forming a superconducting channel layer on gate insulator layer, and forming a source electrode and a drain electrode on said superconducting channel layer.
Claim 19
Independent Claim
177 words
A method for manufacturing a superconducting device, including the step of forming an oxide superconductor thin film on a substrate, depositing an extremely thin insulator layer on said oxide superconductor thin film, forming on a portion of said gate insulator layer a source electrode having an end surface substantially perpendicular to said substrate so that said source electrode is in electrical connection with said oxide superconductor thin film because of flocculation generated in said extremely thin insulator layer, depositing on said end surface of said source electrode a gate electrode in the form of a thin film surrounded by a gate insulator layer in such a manner that a plane of the thin film of said gate electrode is substantially perpendicular to said substrate, and forming on said extremely thin insulator layer a drain electrode adjacent to said gate insulator layer surrounding said gate electrode in the form of a thin film so that said drain electrode is in electrical connection with said oxide superconductor thin film because of flocculation generated in said extremely thin insulator layer.
References Cited (Backward Citations)
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