EP0477103A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for manufacturing superconducting device having a reduced thickness of oxide superconducting layer and superconducting device manufactured thereby
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1991-09-19
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Granted: —
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Expires: 2011-09-19
Abstract
Abstract For manufacturing a superconducting device, a first oxide superconductor thin film having a very thin thickness is formed on a principal surface of a substrate, and a stacked structure of a gate insulator and a gate electrode is 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, using the gate electrode as a mask, so that first and second superconducting regions having a relatively thick thickness are formed at opposite sides of the gate electrode, electrically isolated from the gate electrode. A source electrode and a drain electrode is formed on the first and second oxide superconducting regions. The superconducting device thus formed can functions as a super-FET.
Inventors
- 👤 Takao Cabinet Ballot-Schmit Nakamura
- 👤 Hiroshi Cabinet Ballot-Schmit Inada
- 👤 Michitomo Cabinet Ballot-Schmit Iiyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 04:22
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/20; H10N60/205; H10N60/207; Y; Y10; Y10S; Y10S505/00; Y10S505/70; Y10S505/701; Y10S505/725; Y10S505/728
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
147 words
A method for manufacturing a superconducting device, the method comprising the step of preparing a substrate having a principal surface 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 gate insulator formed directly on a first oxide superconductor thin film and a gate electrode formed on the gate insulator, and growing a second oxide superconductor thin film on an exposed surface of the first oxide superconductor thin film using the gate electrode as a mask, so that first and second superconducting regions having a relatively thick thickness are formed at opposite sides of the gate electrode, electrically isolated from the gate electode, and forming a source electrode and a drain electrode on the first and second oxide superconducting regions, respectively.
Claim 2
Dependent Claim
43 words
A method claimed in Claim 1 wherein the second oxide superconductor thin film is grown on the exposed surface of the first oxide superconductor thin film so that the first and second oxide superconductor thin films constitute a single oxide superconductor thin film.
Claim 3
Dependent Claim
51 words
A method claimed in Claim 2 wherein the first and second oxide superconductor thin films are formed of the same 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 4
Dependent Claim
27 words
A method claimed in Claim 3 wherein the first and second oxide superconductor thin films are disposited to constitute a single c -axis orientates single crystal film.
Claim 5
Dependent Claim
20 words
A method claimed in Claim 4 wherein the gate electrode is formed of a refractory metal or a silicide thereof.
Claim 6
Dependent Claim
28 words
A method claimed in Claim 4 wherein the gate electrode is formed of a material selected from the group consisting of Au, Ti, W, and a silicide thereof.
Claim 7
Dependent Claim
37 words
A method claim in Claim 4 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
36 words
A method claimed in Claim 4 wherein the substrate is formed of a silicon substrate having a principal surface coated with an insulating material layer which is formed of a MgAlO₄ layer and a BaTiO₃ layer.
Claim 9
Dependent Claim
46 words
A method claimed in Claim 4 wherein the gate insulator is formed of an insulating material which does not form a large density of energy levels between the oxide superconductor material of the first oxide superconductor thin film and the insulating material of the gate insulator.
Claim 10
Dependent Claim
42 words
A superconducting device claimed in Claim 4 wherein the first oxide superconductor thin film is formed to have a thickness of about 5 nm and the gate insulator is formed of MgO to have a thickness of not less than 10 nanometers.
Claim 11
Dependent Claim
117 words
A superconducting device claimed in Claim 1 wherein after the stacked structure including the gate insulator and the gate electrode is formed on the portion of the first oxide superconductor thin film, a side surface of at least the gate electrode of the stacked structure is coated with an insulator member, and wherein the second oxide superconductor thin film is grown on a exposed surface of the first oxide superconductor thin film until the stacked structure is completely embedded in the second oxide superconductor thin film, and the second oxide superconductor thin film is planarized until an upper surface of the gate electrode is exposed at the planarized upper surface of the second oxide superconductor thin film.
Claim 12
Dependent Claim
191 words
A superconducting device comprising a substrate having a principal surface, first and second oxide superconducting regions of a relatively thick thickness formed on the principal surface of the substrate separated from each other, and a third oxide superconducting region of an extremely thin thickness formed on the principal surface of the substrate beetween the first and second oxide superconducting regions to bridge the first and second oxide superconducting regions and to form a superconducting regions, a source electrode and a drain electrode provided on the first and second oxide superconducting regions, respectively, so that a superconducting current can flow through the superconducting channel between the source electrode and the drain electrode, a gate electrode formed through a gate insulator on the third oxide superconducting region for controlling the superconducting current flowing through the superconducting channel, and a side insulating region formed to completely cover each of opposite side surfaces of the gate electrode, the first, second and third oxide superconducting regions being formed of the same oxide superconductor thin film, and the gate electrode being surrounded by the oxide superconductor thin film by the gate insulator and the side insulating region.
Claim 13
Dependent Claim
47 words
A superconducting device claimed in Claimed 12 wherein the oxide superconductor thin film is formed of an oxide superconductor material selected from the group consisting of 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 14
Dependent Claim
27 words
A superconducting device claimed in Claim 13 wherein the first, second and third oxide superconducting regions are formed of a single c -axis orientated single crystal film.
Claim 15
Dependent Claim
20 words
A superconducting device claimed in Claim 14 the gate electrode is formed of a refractory metal or a silicide thereof.
Claim 16
Dependent Claim
29 words
A superconducting device claimed in Claim 14 wherein the gate electrode is formed of a material selected from the group consiting of Au, Ti, W, and a silicide thereof.
Claim 17
Dependent Claim
37 words
A superconducting device claimed in Claim 14 wherein the substrate is formed of a material selected from the group consisting of a MgO (100) substrate, a SrTiO₃ (100) substrate and CdNdAlO₄ (001) substrate, and a semiconductor substrate.
Claim 18
Dependent Claim
37 words
A superconducting device claimed in Claim 14 wherein the substrate is formed of a silicon substrate having a principal surface coated with an insulating material layer which is formed of a MgAlO₄ layer and a BaTiO₃ layer.
Claim 19
Dependent Claim
31 words
A superconducting device claimed in Claim 14 wherein the gate insulator is formed of a metal stable to the oxide superconductor material of the first, second and third oxide superconducting regions.
Claim 20
Dependent Claim
38 words
A superconducting device claimed in Claim 14 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 21
Dependent Claim
60 words
A superconducting device claimed in Claim 14 wherein the side insulating region is formed of an insulator material, and the gate electrode is embedded in the oxide superconductor thin film so that the gate electrode is isolated from the first, second and third oxide superconducting regions by the gate insulator and the side insulation region formed of the insulator material.
References Cited (Backward Citations)
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