US4722852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for electron emission including device for providing work function reducing layer and method of applying such a layer
Assignee: US Philips Corp
•
Filing: 1987-05-21
•
Granted: 1988-02-02
•
Expires: 2007-05-21
Abstract
Abstract An electron-emitting surface is provided with a material reducing the electron work function, which is obtained from a suitable reaction. The reaction mixture or the product to be decomposed, for example CsN 3 , is present in a surface depression of a semiconductor body, while one or more pn junctions act as a heating diode. Upon heating, cesium is released and deposited on the electron-emitting surface.
Inventors
- 👤 Arthur M. E. Hoeberechts
- 👤 Henricus A. M. Van Hal
- 👤 Harm Tolner
- 👤 Gerardus G. P. van Gorkom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:45
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/32; H01J1/13; H01J1/30; H01J1/308; H01J1/34; H01J2201/00; H01J2201/34; H01J2201/342; H01J2201/3421; H01J2201/3423
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
103 words
A method of coating an electron-emitting surface with a layer of material reducing the electron work function of the surface, the surface located in an envelope which is evacuated or filled with an inert protective gas, the method comprising heating a source of the material located in the envelope, whereby the material is released from the source and deposited on the electron-emitting surface, characterized in that the source is placed on a semiconductor device located in the envelope, the device comprising a semiconductor body and electrical leads, and further characterized in that the source is heated by supplying current to the semiconductor device.
Claim 2
Independent Claim
103 words
A method of coating an electron-emitting surface with a layer of material reducing the electron work function of the surface, the surface located in an envelope which is evacuated or filled with an inert protective gas, the method comprising heating a source of the material located in the envelope, whereby the material is released from the source and deposited on the electron-emitting surface, characterized in that the source is placed on a semiconductor device located in the envelope, the device comprising a semiconductor body and electrical leads, and further characterized in that the source is heated by supplying current to the semiconductor device.
Claim 3
Dependent Claim
21 words
The method of claim 1 in which the semiconductor body has a pn junction and the semiconductor device is a diode.
Claim 4
Dependent Claim
17 words
The method of claim 1 in which the semiconductor body has a surface depression for the source.
Claim 5
Dependent Claim
25 words
The method of claim 1 in which the material reducing the electron work function is cesium, and is released during the decomposition of cesium azide.
Claim 6
Dependent Claim
19 words
The method of claim 4 in which the leads of the semiconductor device are covered with a protective layer.
Claim 7
Dependent Claim
18 words
The method of claim 5 in which the protective layer is selected from silicon nitride and silicon oxynitride.
Claim 8
Dependent Claim
36 words
The method of claim 1 in which the semiconductor device is situated within a substantially closed space in the envelope, the space having at least one outlet opening for the material reducing the electron work function.
Claim 9
Dependent Claim
20 words
The method of claim 1 in which the layer of the material reducing the electron work function is a monolayer.
Claim 10
Dependent Claim
31 words
The method of claim 1 in which the thickness of the layer of the material reducing the electron work function is varied by varying the current supplied to the semiconductor device.
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) | 1991-02-01 | 1991-08-03 | 1992-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-01 | 1995-08-03 | 1996-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-01 | 1999-08-03 | 2000-02-02 | $7700.00 | Window Closed / Lapsed |