US4786957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Negative differential resistance element
Assignee: National Institute of Advanced Industrial Science and Technology
•
Filing: 1987-01-29
•
Granted: 1988-11-22
•
Expires: 2007-01-29
Abstract
Abstract A negative differential resistance element, the characteristics of which can be modulated externally, is provided by a sequential arrangement of an n-type GaAs emitter layer, a non-doped AlGaAs first barrier layer, an n-type GaAs base layer, a second barrier layer of a superlattice composed of coupled non-doped AlAs and GaAs thin layers, and an n-type collector layer. The conductivity of the emitter, base, and collector layers may be changed to p-type.
Inventors
- 👤 Shunichi Muto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:21
CPC Classifications
B; B82; B82Y; B82Y10/00; H; H10; H10D; H10D48/00; H10D48/30; H10D48/32; H10D48/36; H10D48/362; H10D62/00; H10D62/80; H10D62/81; H10D62/815
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
161 words
A negative differential resistance element, comprising a GaAs emitter layer of one conductivity type; a first barrier layer of non-doped AlGaAs in contact with the emitter layer; a GaAs base layer of the one conductivity type in contact with the first barrier layer on the opposite side of the emitter layer; a second barrier layer of a superlattice composed of a plurality of coupled non-doped AlAs and GaAs thin layers in contact with the base layer on the opposite side of the first barrier layer; a GaAs collector layer of the one conductivity type in contact with the second barrier layer on the opposite side of the base layer; an emitter electrode connected to the emitter layer; a base electrode connected to the base layer; a collector electrode connected to the collector layer; and, means for biasing the element so that a carrier of said one conductivity type flows from the emitter layer to the collector layer via the base layer.
Claim 2
Dependent Claim
161 words
A negative differential resistance element, comprising a GaAs emitter layer of one conductivity type; a first barrier layer of non-doped AlGaAs in contact with the emitter layer; a GaAs base layer of the one conductivity type in contact with the first barrier layer on the opposite side of the emitter layer; a second barrier layer of a superlattice composed of a plurality of coupled non-doped AlAs and GaAs thin layers in contact with the base layer on the opposite side of the first barrier layer; a GaAs collector layer of the one conductivity type in contact with the second barrier layer on the opposite side of the base layer; an emitter electrode connected to the emitter layer; a base electrode connected to the base layer; a collector electrode connected to the collector layer; and, means for biasing the element so that a carrier of said one conductivity type flows from the emitter layer to the collector layer via the base layer.
Claim 3
Dependent Claim
27 words
An element according to claim 1, wherein each of the thin AlAs layers in the second barrier layer has a thickness of a heptatomic layer or less.
Claim 4
Dependent Claim
27 words
An element according to claim 1, wherein each of the thin GaAs layers in the second barrier layer has a thickness of a hexatomic to dodecatomic layer.
Claim 5
Dependent Claim
21 words
An element according to claim 1, wherein the number of the coupled thin AlAs and GaAs layers is ten or more.
Claim 6
Dependent Claim
19 words
An element according to claim 1, wherein the thickness of the second barrier layer is 1000 Å or more.
Claim 7
Dependent Claim
19 words
An element according to claim 1, wherein the thickness of the first barrier layer is 200 Å or less.
Claim 8
Dependent Claim
67 words
A negative differential resistance element as recited in claim 1 wherein said emitter and base electrodes constitute an input for an emitter-based voltage V EB , said collector electrode constitutes an output for a current I C , and said means for biasing the element is a base-collector voltage V BC applied to said base and collector electrodes for controlling negative differential resistance characteristic of said element.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-22 | 1992-05-23 | 1992-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-22 | 1996-05-23 | 1996-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-22 | 2000-05-23 | 2000-11-22 | $7700.00 | Window Closed / Lapsed |