US5229360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming a multilayer superconducting circuit
Assignee: Furukawa Electric Co Ltd
•
Filing: 1992-02-06
•
Granted: 1993-07-20
•
Expires: 2012-02-06
Abstract
Abstract A method for forming a superconducting circuit is disclosed, comprising the steps of forming a mask pattern on a superconducting layer, forming a covering layer, containing a modifying element for superconductor, on the resultant structure, diffusing the modifying element for a superconductor, which is contained in the covering layer, into the superconducting layer to modify a corresponding location to a nonsuperconducting layer. A method for forming a multi-layer superconducting circuit is also disclosed, comprising sequentially repeating the same steps as set forth above over a substrate.
Inventors
- 👤 Shoji Shiga
- 👤 Koki Sato
- 👤 Nakahiro Harada
- 👤 Kiyoshi Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:32
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/0661; Y; Y10; Y10S; Y10S505/00; Y10S505/70; Y10S505/701; Y10S505/725; Y10S505/73; Y10S505/731
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
261 words
A method for forming a multi-layer superconducting circuit structure having multiple superconducting layers, comprising the steps of: (1) epitaxially growing a ceramic superconducting layer on a substrate; (2) forming a mask pattern on a circuit portion of said ceramic superconducting layer; (3) covering the surface of said ceramic superconducting layer, including said circuit portion having said mask pattern formed thereon and a non-circuit portion not having said mask pattern formed thereon, with a covering layer comprising a modifying element selected from the group consisting of Zn, Ga, Fe, Co, Ni, La, Cd and Be, for lowering the critical temperature of said ceramic superconducting layer; (4) removing from said circuit portion of said ceramic superconducting layer said mask pattern together with said covering layer formed thereon to form a partially covered ceramic superconducting layer still covered by said covering layer in said non-circuit portion; (b 5) heating said partially covered ceramic superconducting layer so as to thermally diffuse said modifying element from said covering layer into said non-circuit portion of said ceramic superconducting layer, thereby forming a layer of a superconducting circuit structure including a superconducting circuit portion and a non-superconducting non-circuit portion, said circuit portion having a critical temperature of more than 77K, and said non-circuit portion having a critical temperature less than 77K and a crystal structure the same as or similar to that of the circuit portion; and (6) repeating at least once on said layer of said superconducting circuit structure said steps (1) to (5) to thereby form said multi-layer superconducting circuit structure having said multiple superconducting layers.
Claim 2
Independent Claim
261 words
A method for forming a multi-layer superconducting circuit structure having multiple superconducting layers, comprising the steps of: (1) epitaxially growing a ceramic superconducting layer on a substrate; (2) forming a mask pattern on a circuit portion of said ceramic superconducting layer; (3) covering the surface of said ceramic superconducting layer, including said circuit portion having said mask pattern formed thereon and a non-circuit portion not having said mask pattern formed thereon, with a covering layer comprising a modifying element selected from the group consisting of Zn, Ga, Fe, Co, Ni, La, Cd and Be, for lowering the critical temperature of said ceramic superconducting layer; (4) removing from said circuit portion of said ceramic superconducting layer said mask pattern together with said covering layer formed thereon to form a partially covered ceramic superconducting layer still covered by said covering layer in said non-circuit portion; (b 5) heating said partially covered ceramic superconducting layer so as to thermally diffuse said modifying element from said covering layer into said non-circuit portion of said ceramic superconducting layer, thereby forming a layer of a superconducting circuit structure including a superconducting circuit portion and a non-superconducting non-circuit portion, said circuit portion having a critical temperature of more than 77K, and said non-circuit portion having a critical temperature less than 77K and a crystal structure the same as or similar to that of the circuit portion; and (6) repeating at least once on said layer of said superconducting circuit structure said steps (1) to (5) to thereby form said multi-layer superconducting circuit structure having said multiple superconducting layers.
Claim 3
Dependent Claim
36 words
The method according to claim 1 wherein a diffusion amount of the modifying element is below a range in which a crystal structure of the ceramic superconducting layer is sustained after said diffusing has been performed.
Claim 4
Dependent Claim
25 words
The method according to claim 1, wherein said ceramic superconducting layer is selected from the group consisting of a Y-Ba-Cu-O superconductor and a Tλ-Ba-Ca-Cu-O superconductor.
Claim 5
Dependent Claim
16 words
The method according to claim 1, wherein said mask pattern is formed by a photolithography method.
Claim 6
Dependent Claim
32 words
The method according to claim 1, wherein said covering layer comprising said modifying element is formed by a forming method selected from the group consisting of sputtering, vapor deposition and ion plating.
Claim 7
Dependent Claim
22 words
The method according to claim 1, wherein the heating step 5 is performed at a temperature of 200° C. to 1000° C.
Claim 8
Dependent Claim
20 words
The method according to claim 1, wherein a buffer layer is provided between layers of said multi-layer superconducting circuit structure.
Claim 9
Dependent Claim
37 words
The method according to claim 7, wherein said buffer layer is made of a material selected from the group consisting of MgO, SrTiO 3 , AλGaO 3 , ZrO 2 , BaZrO 3 and LaAlO 3 .
Claim 10
Dependent Claim
16 words
The method according to claim 1, wherein said ceramic superconducting layer comprises a Y-Ba-Cu-O superconducting layer.
Claim 11
Dependent Claim
21 words
The method according to claim 1, wherein said ceramic superconducting layer comprises YBa 2 .1 Cu 2 .2 O 7 .1.
Claim 12
Dependent Claim
53 words
The method according to claim 1, wherein said heating step 5 is performed at a temperature of 200° C. to 1000° C.; said covering layer is formed by a forming method selected from the group consisting of sputtering, vapor deposition and ion plating; and said mask pattern is formed by a photolithography method.
Claim 13
Dependent Claim
21 words
The method according to claim 11, wherein said ceramic superconducting layer comprises YBa 2 .1 Cu 2 .2 O 7 .1.
Claim 14
Dependent Claim
60 words
The method according to claim 7, wherein said ceramic superconducting layers comprise a Y-Ba-Cu-O superconductor; said heating step 5 is performed at a temperature 200° C. to 1000° C.; said covering layer is formed by a forming method selected from the group consisting of sputtering, vapor deposition and ion plating; and said mask pattern is formed by a photolithography method.
Claim 15
Dependent Claim
28 words
The method according to claim 7, wherein said buffer layer comprises SrTiO 3 and said ceramic superconducting layers comprise YBa 2 .1 Cu 2 .2 O 7 .1.
References Cited (Backward Citations)
US4376138A
Cited
US4758525A
Cited
EP0282360A2
Cited
JPS63258083A
Cited
US4900709A
Cited
US5051396A
Cited
JPS6473780A
Cited
US4971948A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-19 | 1997-01-18 | 1997-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-19 | 2001-01-18 | 2001-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-19 | 2005-01-18 | 2005-07-20 | $7700.00 | Window Closed / Lapsed |