US4352117A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron source
Assignee: International Business Machines Corp
•
Filing: 1980-06-02
•
Granted: 1982-09-28
•
Expires: 2000-06-02
Abstract
Abstract A high brightness, essentially monoenergetic electron source is constructed in solid state material by providing a semiconductor body with an electron confinement barrier over most of the surface, the barrier having a relatively small opening exposing the semiconductor body, in the relatively small opening a material is placed in contact with the semiconductor body that has a work function that is lower than the energy of excited electrons in the semiconductor. In this structure electrons from hole-electron pairs generated in the semiconductor are repelled and recombination is inhibited by the barrier except in the relatively small opening where they are injected into the surrounding environment through the lower work function material. The hole-electron pair generation may be by irradiation or by electrical injection. The electron source is useful for such applications as high brightness sources, digital communications, cathode ray tube electron sources and scanning electron microscopes.
Inventors
- 👤 Jerome J. Cuomo
- 👤 Russell W. Dreyfus
- 👤 Jerry M. Woodall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:18
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/30; H01J1/308
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
90 words
An electron source comprising in combination: a p-type gallium arsenide semiconductor region in which hole-electron pairs can be generated, said region having the property of a specific electron diffusion length, an electron barrier layer of gallium aluminum arsenide on at least a portion of the surface thereof, said barrier layer having an emission opening exposing a portion of the surface of said semiconductor region, a negative electron affinity material in contact with the exposed surface of said emission opening, and means for generating hole electron pairs in said semiconductor region.
Claim 2
Dependent Claim
90 words
An electron source comprising in combination: a p-type gallium arsenide semiconductor region in which hole-electron pairs can be generated, said region having the property of a specific electron diffusion length, an electron barrier layer of gallium aluminum arsenide on at least a portion of the surface thereof, said barrier layer having an emission opening exposing a portion of the surface of said semiconductor region, a negative electron affinity material in contact with the exposed surface of said emission opening, and means for generating hole electron pairs in said semiconductor region.
Claim 3
Dependent Claim
15 words
The electron source of claim 1 wherein said means of generating carriers is by irradiation.
Claim 4
Dependent Claim
18 words
The electron source of claim 1 wherein said means of generating hole-electron pairs is by electrical carrier injection.
Claim 5
Dependent Claim
88 words
The electron source of claim 1 wherein the material of said semiconductor region is gallium arsenide, said electron barrier forming layer material is epitaxial gallium aluminum arsenide of the same conductivity type as the material of said semiconductor region and said electron-hole pair injection is produced by injecting from an epitaxial injection region of gallium aluminum arsenide contiguous with a surface of said semiconductor region opposite to that of said opening, said injection region having a conductivity type opposite to that of the material of said semiconductor region.
Claim 6
Dependent Claim
73 words
In an electron emission device of the type wherein electrons present as excited non-equilibrium carriers in a p-type semiconductor are caused to be emitted through a confined emission surface area of said p-type semiconductor through a negative electron affinity material, the improvement comprising: providing a p-conductivity type barrier region to excited non-equilibrium electron flow over at least the portion of the surface area of said p-type semiconductor surrounding said confined emission surface area.
Claim 7
Dependent Claim
73 words
In an electron emission device of the type wherein electrons present as excited non-equilibrium carriers in a p-type semiconductor are caused to be emitted through a confined emission surface area of said p-type semiconductor through a negative electron affinity material, the improvement comprising: providing a p-conductivity type barrier region to excited non-equilibrium electron flow over at least the portion of the surface area of said p-type semiconductor surrounding said confined emission surface area.
Claim 8
Dependent Claim
35 words
The device of claim 5 wherein said barrier is formed between said p-type semiconductor and an atomically compatible p-type layer having at least one of a change in doping and a larger energy band gap.
Claim 9
Dependent Claim
20 words
The device of claim 5 wherein said barrier is of a potential of the order of at least 4 KT.
Claim 10
Dependent Claim
40 words
The device of claim 6 wherein said semiconductor is gallium arsenide and said barrier is formed between said gallium arsenide and at least one of an atomically compatible layer having a change in doping, or a larger energy band gap.
Claim 11
Dependent Claim
14 words
The device of claim 8 wherein said barrier forming layer is gallium aluminum arsenide.
Claim 12
Dependent Claim
20 words
The device of claim 6 where the semiconductor is indium arsenide phosphide and the barrier forming layer is indium phosphide.
References Cited (Backward Citations)
GB1275972A
Cited
US3696262A
Cited
US3667007A
Cited
US3699404A
Cited
US3808477A
Cited
USB309756I5
Cited
US3972060A
Cited
GB1476471A
Cited
US3972750A
Cited
US3959037A
Cited
US4040079A
Cited
US4040074A
Cited
US4040080A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-09-27 | 1986-03-29 | 1986-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-27 | 1990-03-29 | 1990-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-27 | 1994-03-29 | 1994-09-28 | $7700.00 | Window Closed / Lapsed |