US4575741A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cryogenic transistor with a superconducting base and a semiconductor-isolated collector
Assignee: International Business Machines Corp
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Filing: 1984-04-26
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Granted: 1986-03-11
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Expires: 2004-04-26
Abstract
Abstract This invention relates generally to cryogenic amplifying-switching devices and more specifically relates to a cryogenic transistor with a superconducting base and a collector isolated from the base by a semiconductor element. Still more specifically, the invention is directed to a three terminal, transistor-like device which incorporates three metal layers. The first and second of the three layers are separated by an insulating tunnel barrier and the second and third layers are separated by a semiconductor layer of a thickness sufficient to inhibit tunnelling. The semiconductor layer has a barrier height (low) which is sufficient to permit the passage of quasiparticles from the second layer while simultaneously inhibiting the passage of Cooper pairs. The second layer is a superconductor while the first and third layers may be superconductors or normal metals. The second and third layers are connected to the semiconductor layer by means of ohmic contacts.
Inventors
- 👤 David J. Frank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:31
CPC Classifications
H; H10; H10N; H10N70/00; H10N60/00; H10N60/10; H10N60/128; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/873
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
88 words
A superconducting transistor comprising: a layer of superconductive material, a layer of conductive material, means disposed between said layers for controlling the flow between said layers of quasiparticles which are generated in said layer of superconductive material and for simultaneously inhibiting the tunnelling of Cooper pairs and the flow of carriers from said layer of conductive material to said layer of superconductive material, said layer of superconductor material and said layer of conductive material being connected to said means for controlling and inhibiting by means of ohmic contacts.
Claim 2
Dependent Claim
88 words
A superconducting transistor comprising: a layer of superconductive material, a layer of conductive material, means disposed between said layers for controlling the flow between said layers of quasiparticles which are generated in said layer of superconductive material and for simultaneously inhibiting the tunnelling of Cooper pairs and the flow of carriers from said layer of conductive material to said layer of superconductive material, said layer of superconductor material and said layer of conductive material being connected to said means for controlling and inhibiting by means of ohmic contacts.
Claim 3
Dependent Claim
68 words
A superconducting transistor according to claim 1 wherein said means for controlling and inhibiting is a layer of semiconductive material having a barrier height sufficient to permit the passage of said quasiparticles and to inhibit the flow of said carriers from said layer of conductive material to said layer of superconductive material and a thickness sufficient to inhibit tunnelling of said Cooper pairs and to minimize impact ionization.
Claim 4
Dependent Claim
27 words
A superconducting transistor according to claim 1 further including means connected to said layer of superconductive material for generating said quasiparticles in said layer of superconductive material.
Claim 5
Dependent Claim
39 words
A superconducting transistor according to claim 1 further including biasing means connected to said layers of superconductive and conductive material for initiating and halting the flow of said quasiparticles and load means connected to said layer of conductive material.
Claim 6
Dependent Claim
15 words
A superconducting transistor according to claim 1 wherein said layer of superconductive material comprises tantalum.
Claim 7
Dependent Claim
28 words
A superconducting transistor according to claim 1 wherein said layer of conductive material is a material selected from the group consisting of normal metals, superconductors and degenerate semiconductors.
Claim 8
Dependent Claim
27 words
A superconducting transistor according to claim 2 further including means connected to said layer of superconductive material for generating said quasiparticles in said layer of superconductive material.
Claim 9
Dependent Claim
39 words
A superconducting transistor according to claim 2 further including biasing means connected to said layers of superconductive and conductive material for initiating and halting the flow of said quasiparticles and load means connected to said layer of conductive material.
Claim 10
Dependent Claim
15 words
A superconducting transistor according to claim 2 wherein said layer of superconductive material comprises tantalum.
Claim 11
Dependent Claim
28 words
A superconducting transistor according to claim 2 wherein said layer of conductive material is a material selected from the group consisting of normal metals, superconductors and degenerate semiconductors.
Claim 12
Dependent Claim
22 words
A superconducting transistor according to claim 2 wherein said layer of semiconductive material comprises a semiconductor doped with a p-conductivity type dopant.
Claim 13
Dependent Claim
22 words
A superconducting transistor according to claim 2 wherein said layer of semiconductive material comprises a semiconductor doped with an n-conductivity type dopant.
Claim 14
Dependent Claim
28 words
A superconducting transistor according to claim 2 wherein said layer of semiconductive material comprises a semiconductor doped with a p-conductivity type dopant to a doping level approaching degeneracy.
Claim 15
Dependent Claim
28 words
A superconducting transistor according to claim 2 wherein said layer of semiconductive material comprises a semiconductor doped with an n-conductivity type dopant to a doping level approaching degeneracy.
Claim 16
Dependent Claim
28 words
A superconducting transistor according to claim 2 wherein said layer of semiconductive material comprises a semiconductor selected from the group consisting of gallium antimonide, indium antimonide and germanium.
Claim 17
Dependent Claim
42 words
A superconducting transistor according to claim 2 wherein said layer of semiconductive material comprises a semiconductor selected from the group consisting of gallium antimonide, indium antimonide and germanium, said semiconductor being doped with a p-conductivity type dopant to a level approaching degeneracy.
Claim 18
Dependent Claim
41 words
A superconducting transistor according to claim 3 wherein said means for generating is a source of light from which light of sufficient energy to create quasiparticles in said layer of superconductive material is applied directly to said layer of superconductive material.
Claim 19
Dependent Claim
30 words
A superconducting transistor according to claim 3 wherein said means for generating is a layer of conductive material spaced from said layer of superconductive material by a layer of insulation.
Claim 20
Dependent Claim
17 words
A superconducting transistor according to claim 6 wherein said layer of conductive material comprises tantalum and aluminum.
Claim 21
Dependent Claim
32 words
A superconducting transistor according to claim 7 wherein said means for generating is a layer of superconductive or normal metal spaced from said layer of superconductive material by a layer of insulation.
Claim 22
Dependent Claim
41 words
A superconducting transistor according to claim 7 wherein said means for generating is a source of light from which light of sufficient energy to create quasiparticles in said layer of superconductive material is applied directly to said layer of superconductive material.
Claim 23
Dependent Claim
47 words
A superconducting transistor according to claim 20 further including biasing means connected to said layers of superconductive and conductive material and said layer of superconducting or normal metal for initiating and halting the flow of said quasiparticles and load means connected to said layer of conductive material.
Claim 24
Dependent Claim
26 words
A superconducting transistor according to claim 22 wherein said layers of superconductive and conductive material are connected to said semiconductive material by means of ohmic contacts.
Claim 25
Dependent Claim
15 words
A superconducting transistor according to claim 23 wherein said layer of superconductive material comprises tantalum.
Claim 26
Dependent Claim
28 words
A superconducting transistor according to claim 23 wherein said layer of conductive material is a material selected from the group consisting of normal metals, superconductors and degenerate semiconductors.
Claim 27
Dependent Claim
22 words
A semiconducting transistor according to claim 23 wherein said layer of semiconductive material comprises a semiconductor doped with a p-conductivity type dopant.
Claim 28
Dependent Claim
22 words
A superconducting transistor according to claim 23 wherein said layer of semiconductive material comprises a semiconductor doped with an n-conductivity type dopant.
Claim 29
Dependent Claim
28 words
A superconducting transistor according to claim 23 wherein said layer of semiconductive material comprises a semiconductor doped with a p-conductivity type dopant to a doping level approaching degeneracy.
Claim 30
Dependent Claim
28 words
A superconducting transistor according to claim 23 wherein said layer of semiconductive material comprises a semiconductor doped with an n-conductivity type dopant to a doping level approaching degeneracy.
Claim 31
Dependent Claim
42 words
A superconducting transistor according to claim 23 wherein said layer of semiconductive material comprises a semiconductor selected from the group consisting of gallium antimonide, indium antimonide and germanium said semiconductor being doped with a p-conductivity type dopant to a level approaching degeneracy.
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