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US3928671A
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Process for fabricating a solid state, thin film field sustained conductivity device
Assignee: Raytheon Co
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Filing: 1973-11-12
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Granted: 1975-12-23
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Expires: 1993-11-12
Abstract
Abstract An electrical field sustained conductivity device is fabricated by successively disposing over a layer of cadmium sulfide a film of metal particles and a composite layer of metal particles in an insulating medium. When a potential is applied across the cadmium sulfide layer, an image may be stored therein by momentarily exposing the layer to electrons or light conveying that image. Such exposure introduces conductivity changes in the cadmium sulfide layer by virtue of the layers deposited on it and the conductivity changes are retained so long as the applied potential is maintained.
Inventors
- 👤 Paul F Robusto
- 👤 Craig P Stephens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:07
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/20; H01J9/233; H01J29/00; H01J29/02; H01J29/10; Y; Y10; Y10S; Y10S257/00; Y10S257/917
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
139 words
IN THE PROCESS OF FABRICATING AN ELECTRICAL FIELD SUSTAINED CONDUCTIVELY DEVICE OF THE TYPE HAVING A LAYER OF HEAT-TREATED CADMIUM SULFIDE FORMED BETWEEN A BOTTOM ELECTRODE CONSISTING OF AN OPTICALLY TRANSPARENT, ELECTRICALLY CONDUCTIVE COATING DISPOSED ONAN OPTICAL TRANSPAENT SUBSTRATE AND A TOP ELECTRODE WHICH IS DEPOSITED ON A COMPOSITE FILM WHICH IS APPLIED TO SAID CADIUM SULFIDE LAYER, THE STEPS OF: A. APPLYING TO SAID LAYER OF HEATED-TREATED CADIUM SULFIDE BETWEEN SAID LAYER AND ONE OF SAID ELECTRODES A DISCONTINUOUS LAYER OF METAL PLATELETS, SAID METAL BEING SELECTED FROM A GROUP CONSISTING OF SILVER, GOLD, AND PLATINUM; AND B. CO-EVAPORATING ON TO SAID METALLIC LAYER A SECOND METAL AND A DIELECTRIC SO AS TO FORM SAID COMPOSITE FILM, SAID SECOND METAL BEING SELECTED FROM THE GROUP CONSISTING OF GOLD, ALUMINUM, SILVER, AND PALLADIUM AND SAID DIELECTRIC BEING SILICON MONOXIDE.
Claim 2
Dependent Claim
139 words
IN THE PROCESS OF FABRICATING AN ELECTRICAL FIELD SUSTAINED CONDUCTIVELY DEVICE OF THE TYPE HAVING A LAYER OF HEAT-TREATED CADMIUM SULFIDE FORMED BETWEEN A BOTTOM ELECTRODE CONSISTING OF AN OPTICALLY TRANSPARENT, ELECTRICALLY CONDUCTIVE COATING DISPOSED ONAN OPTICAL TRANSPAENT SUBSTRATE AND A TOP ELECTRODE WHICH IS DEPOSITED ON A COMPOSITE FILM WHICH IS APPLIED TO SAID CADIUM SULFIDE LAYER, THE STEPS OF: A. APPLYING TO SAID LAYER OF HEATED-TREATED CADIUM SULFIDE BETWEEN SAID LAYER AND ONE OF SAID ELECTRODES A DISCONTINUOUS LAYER OF METAL PLATELETS, SAID METAL BEING SELECTED FROM A GROUP CONSISTING OF SILVER, GOLD, AND PLATINUM; AND B. CO-EVAPORATING ON TO SAID METALLIC LAYER A SECOND METAL AND A DIELECTRIC SO AS TO FORM SAID COMPOSITE FILM, SAID SECOND METAL BEING SELECTED FROM THE GROUP CONSISTING OF GOLD, ALUMINUM, SILVER, AND PALLADIUM AND SAID DIELECTRIC BEING SILICON MONOXIDE.
Claim 3
Dependent Claim
40 words
The steps of claim 1 characterized further in that said platelets are less than ten microns in diameter and are brushed onto said cadmium sulfide so that they are spaced less than half a micron apart in a single layer.
Claim 4
Dependent Claim
121 words
In the process of fabricating an electrical field sustained conductivity device of the type having a layer of heat-treated cadmium sulfide formed between a bottom electrode consisting of an optically transpatent, electrically conductive coating disposed on an optically transparent substrate and a top electrode which is deposited on a composite film which is applied to said cadmium sulfide layer, the steps of: a. forming on said layer of heat-treated cadmiun sulfide between said layer and one of said electrodes a discontinuous layer of metallic platelets operative to create an array of electrically isolated Schottky barriers in said cadmium sulfide, and b. forming on said metal layer said composite film having ionizable sites due to conductive particles dispersed in an insulating medium.
Claim 5
Dependent Claim
121 words
In the process of fabricating an electrical field sustained conductivity device of the type having a layer of heat-treated cadmium sulfide formed between a bottom electrode consisting of an optically transpatent, electrically conductive coating disposed on an optically transparent substrate and a top electrode which is deposited on a composite film which is applied to said cadmium sulfide layer, the steps of: a. forming on said layer of heat-treated cadmiun sulfide between said layer and one of said electrodes a discontinuous layer of metallic platelets operative to create an array of electrically isolated Schottky barriers in said cadmium sulfide, and b. forming on said metal layer said composite film having ionizable sites due to conductive particles dispersed in an insulating medium.
Claim 6
Dependent Claim
46 words
The steps of claim 1 characterized further in that said metal layer is formed by applying metal platelets less than ten microns in diameter in a single layer to said cadmium sulfide layer, said metal being selected from a group consisting of silver, gold, and platinum.
Claim 7
Dependent Claim
24 words
The steps of claim 1 characterized further in that said composite film is formed by co-evaporating a metal and dielectric onto said metal film.
Claim 8
Dependent Claim
32 words
The steps of claim 3 characterized further in that said discontinuous metal layer is formed by applying a single layer of spaced-apart metal particles in platelet form to said cadmium sulfide layer.
Claim 9
Dependent Claim
20 words
The steps of claim 6 characterized further in that said metal particles are platelets less than ten microns in diameter.
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) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |