US5240906A
Expired / Lapsed
US
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Enhanced superconducting field-effect transistor
Assignee: International Business Machines Corp
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Filing: 1992-04-07
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Granted: 1993-08-31
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Expires: 2012-04-07
Abstract
Abstract An inverted MISFET structure with a high transition temperature superconducting channel comprises a gate substrate, an interfacial layer with one or more elements of the VIII or IB subgroup of the periodic table of elements, an insulating layer and a high transition temperature superconducting channel. An electric field, generated by a voltage applied to its gate alters the conductivity of the channel.
Inventors
- 👤 Johannes G. Bednorz
- 👤 Jochen D. Mannhart
- 👤 Carl A. Mueller
- 👤 Darrell Schlom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:38
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/20; H10N60/205; H10N60/207; Y; Y10; Y10S; Y10S505/00; Y10S505/70; Y10S505/701; Y10S505/725; Y10S505/729
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
92 words
A field-effect transistor, comprising: a substrate layer having gate contact electrode disposed thereon; an additional layer having a thickness of less than 100 Å, and being diffused into and disposed on said substrate layer; an insulating layer being disposed on said additional layer, said additional layer being an interface between said substrate layer and said insulating layer so as to allow for epitaxy therebetween; and a high transition temperature superconducting current channel layer being disposed on said insulating layer, and having a source contact electrode and a drain contact electrode disposed thereon.
Claim 2
Dependent Claim
92 words
A field-effect transistor, comprising: a substrate layer having gate contact electrode disposed thereon; an additional layer having a thickness of less than 100 Å, and being diffused into and disposed on said substrate layer; an insulating layer being disposed on said additional layer, said additional layer being an interface between said substrate layer and said insulating layer so as to allow for epitaxy therebetween; and a high transition temperature superconducting current channel layer being disposed on said insulating layer, and having a source contact electrode and a drain contact electrode disposed thereon.
Claim 3
Dependent Claim
23 words
A field-effect-transistor according to claim 1, wherein said additional layer comprises an element of the VIII subgroup of the Periodic Table of Elements.
Claim 4
Dependent Claim
13 words
A field-effect-transistor according to claim 2, wherein said element comprises a noble metal.
Claim 5
Dependent Claim
23 words
A field-effect-transistor according to claim 1, wherein said additional layer comprises an element of the IB subgroup of the Periodic Table of Elements.
Claim 6
Dependent Claim
13 words
A field-effect-transistor according to claim 4, wherein said element is a noble metal.
Claim 7
Dependent Claim
30 words
A field-effect-transistor according to claim 1, wherein said additional layer comprises a combination of the elements of the VIII subgroup and the IB subgroup of the Periodic Table of Elements.
Claim 8
Dependent Claim
20 words
A field-effect-transistor according to claim 1, wherein the thickness of said additional layer is between 10 Å and 50 Å.
Claim 9
Dependent Claim
20 words
A field-effect transistor according to claim 1, wherein said substrate layer is at least partly covered by said additional layer.
Claim 10
Dependent Claim
30 words
A field-effect transistor according to claim 6, wherein said additional layer has a lattice constant which is approximately equal to the lattice constants of the substrate layer and insulating layer.
Claim 11
Dependent Claim
17 words
A field-effect-transistor according to claim 1, wherein said substrate layer comprises a compound with a perovskite structure.
Claim 12
Dependent Claim
54 words
A field-effect transistor according to claim 10, wherein said compound having a perovskite structure comprises niobium-doped strontium titanate said additional layer comprises a noble metal having approximately the same lattice constant as said niobium-doped strontium titanate, said insulating layer comprises strontium titanate, and said superconducting channel comprises YBa 2 Cu 3 O 7- δ.
Claim 13
Dependent Claim
29 words
A field-effect transistor according to claim 11, wherein said strontium titanate is doped with a doping factor of between 0.01% and 10%, and wherein said noble metal is platinum.
Claim 14
Dependent Claim
17 words
A field-effect-transistor according to claim 1, wherein said insulating layer comprises a compound with a perovskite structure.
Claim 15
Dependent Claim
21 words
A field-effect-transistor according to claim 1, wherein said high-T c superconducting current channel layer comprises a compound with a perovskite structure.
Claim 16
Dependent Claim
30 words
A field-effect-transistor according to claim 1, wherein said substrate layer, said insulating layer and said high-T c superconducting current channel layer each comprise a compound having the same perovskite structure.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1996-08-30 | 1997-03-01 | 1997-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-30 | 2001-03-01 | 2001-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-30 | 2005-03-01 | 2005-08-31 | $7700.00 | Window Closed / Lapsed |