Patent US4353081A successfully refreshed from Google Patents.
US4353081A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Graded bandgap rectifying semiconductor devices
Assignee: AT&T Inc
•
Filing: 1980-01-29
•
Granted: 1982-10-05
•
Expires: 2000-01-29
Abstract
Abstract A unipolar, rectifying semiconductor device is described. Rectification is produced by an asymmetric potential barrier created by a sawtooth-shaped composition profile of AlxGa1-xAs between layers of n-type GaAs. Single and multiple barriers, as well as doped and undoped barriers, show rectification. Also described is the incorporation of this type of device in an infrared detector, a hot electron transistor and mixer diodes.
Inventors
- 👤 Christopher L. Allyn
- 👤 Arthur C. Gossard
- 👤 William Wiegmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:43
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/825; H10D48/00; H10D48/30; H10D48/32; H10D48/36; H10D48/362; H10D62/00; H10D62/80; H10D62/82; H10D62/824; H10D8/40; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/222
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
98 words
A semiconductor device (10) comprising first and second relatively narrow bandgap semiconductor layers (12, 14) a wider bandgap semiconductor layer (16) interposed between said first and second layers, said wider bandgap layer having a graded bandgap which increases from one of said first and second layers to the other, characterized in that said device is capable of unipolar rectification, and said first and second layers have the same conductivity type, and said wider bandgap layer is a barrier layer having a thickness large enough to prevent substantial tunneling therethrough and smaller than the depletion length of carriers therein.
Claim 2
Dependent Claim
98 words
A semiconductor device (10) comprising first and second relatively narrow bandgap semiconductor layers (12, 14) a wider bandgap semiconductor layer (16) interposed between said first and second layers, said wider bandgap layer having a graded bandgap which increases from one of said first and second layers to the other, characterized in that said device is capable of unipolar rectification, and said first and second layers have the same conductivity type, and said wider bandgap layer is a barrier layer having a thickness large enough to prevent substantial tunneling therethrough and smaller than the depletion length of carriers therein.
Claim 3
Dependent Claim
24 words
The device of claim 1 wherein the bandgap between said second layer (14) and said barrier layer (16) changes abruptly at the interface therebetween.
Claim 4
Dependent Claim
19 words
The device of claim 2 wherein said bandgap changes abruptly in a distance on the order of 5-10 Angstroms.
Claim 5
Independent Claim
15 words
The device of claims 1, 2, or 3 wherein said barrier layer is lowly doped.
Claim 6
Dependent Claim
13 words
The device of claim 4 wherein said first and second layers are n-type.
Claim 7
Dependent Claim
27 words
The device of claim 4 wherein said layers comprise Group III-V compounds selected from the group consisting of GaAs, InAs, AlAs, GaSb and AlSb and mixtures thereof.
Claim 8
Dependent Claim
32 words
A high voltage rectifying device comprising a plurality of devices according to claim 2 connected in series and in which the barrier layers all have their compositions graded in the same direction.
Claim 9
Dependent Claim
28 words
A device comprising a plurality of devices according to claim 2 connected in series and in which the bandgap of adjacent barrier layers is graded in opposite directions.
Claim 10
Dependent Claim
43 words
A mixer diode comprising a device according to claim 1 in which the bandgap of said barrier increases from a minimum value at the interfaces with said first and second layers to a maximum value at a point intermediate in said barrier layer.
Claim 11
Dependent Claim
72 words
A hot electron transistor comprising a device according to claim 2 in which said first layer forms an emitter and said second layer forms a base in combination with a third relatively narrow bandgap semiconductor layer which forms a collector and a second barrier layer according to claim 2 interposed between said second and third layers so that the bandgap of said barrier layers decreases abruptly at the interfaces with said base.
Claim 12
Dependent Claim
63 words
An infrared detector comprising a device according to claim 2 wherein radiation to be detected is made incident upon said first layer in order to optically excite carriers over the potential barrier of said barrier layer, said first layer being thick enough to absorb a substantial portion of said radiation and being thinner than the electron mean free path in said first layer.
References Cited (Backward Citations)
US3132057A
Cited
US3626328A
Cited
US3965347A
Cited
US4149174A
Cited
US4160238A
Cited
US4122476A
Cited
US4176366A
Cited
US4137542A
Cited
US4173763A
Cited
US4186407A
Cited
US4163237A
Cited
US4194935A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-04 | 1986-04-05 | 1986-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-04 | 1990-04-05 | 1990-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-04 | 1994-04-05 | 1994-10-05 | $7700.00 | Window Closed / Lapsed |