Patent US3962337A successfully refreshed from Google Patents.
Patent US3573753A successfully refreshed from Google Patents.
US3573753A
Expired / Lapsed
US
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Information storage and retrieval employing an electron beam
Assignee: General Electric Co
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Filing: 1968-08-01
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Granted: 1971-04-06
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Expires: 1988-08-01
Abstract
Abstract A storage medium is described wherein coded information is destructively written by selectively inducing breakdown in a threshold biased capacitor having an electron sensitive variable conductivity layer positioned therein. In one specific embodiment, a hexachlorobutadiene dielectric layer and a juxtaposed lead oxide semiconductive layer are sandwiched between a tin oxide electrode and an electron transparent aluminum electrode. After threshold biasing the structure in a direction opposing conductivity in the lead oxide layer, a 10 kv. electron beam is selectively penetrated into the layer of lead oxide to induce conductivity therein thereby shifting the biasing voltage division in the storage medium to effect a localized dielectric breakdown in the hexachlorobutadiene. The dielectric breakdown in the hexachlorobutadiene selectively ruptures both the dielectric layer and the aluminum electrode thereover producing 10- 50 mil diameter apertures at points of electron beam irradiation. Information is readout by reverse biasing the storage medium and selectively scanning the medium with an electron beam. In a preferred embodiment, a semiconductive wafer is substituted for the tin oxide electrode to permit readout of the recorded information unimpeded by capacitive coupling between the electrodes.
Inventors
- 👤 David W Skelly
- 👤 Robert F Kopczewski
- 👤 James F Burgess
- 👤 Sterling P Newberry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:27
CPC Classifications
G; G11; G11C; G11C13/00; G11C13/04; G11C13/048
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
77 words
An information storage medium comprising a laminar structure having first and second electrodes, at least one of said electrodes being transparent to an electron beam, and a semiconductor material positioned between said electrodes characterized by an increased electrical conductivity upon irradiation with an electron beam, said semiconducting material increasing in conductivity upon electron beam irradiation to produce a breakdown in said laminar structure at said points of irradiation causing a permanent physical deformation of said laminaR structure.
Claim 2
Dependent Claim
77 words
An information storage medium comprising a laminar structure having first and second electrodes, at least one of said electrodes being transparent to an electron beam, and a semiconductor material positioned between said electrodes characterized by an increased electrical conductivity upon irradiation with an electron beam, said semiconducting material increasing in conductivity upon electron beam irradiation to produce a breakdown in said laminar structure at said points of irradiation causing a permanent physical deformation of said laminaR structure.
Claim 3
Dependent Claim
28 words
An information storage medium according to claim 1 wherein at least one electrode has exploded away apertures produced by dielectric breakdown in irradiated portions of said recording medium.
Claim 4
Dependent Claim
26 words
An information storage medium according to claim 1 including means biasing said laminar structure to a threshold level below the dielectric breakdown level of said structure.
Claim 5
Dependent Claim
30 words
An information storage medium according to claim 1 wherein said material between said electrodes include a dielectric layer less than 5 mils thick and a juxtaposed layer of lead oxide.
Claim 6
Dependent Claim
72 words
An information storage medium according to claim 1 wherein one electrode is a semiconductive radiation detecting wafer comprising a p-region of substantially uniform thickness extending beneath the wafer face proximate the variable conductivity material and an n-type region of substantially uniform thickness extending to a predetermined depth beneath the face of said wafer remote from said variable conductivity material so as to leave a depletion region between said p-type and n-type regions.
Claim 7
Dependent Claim
45 words
An information storage medium according to claim 5 wherein a layer of lead oxide is positioned atop the p-type region of said semiconductive wafer, a dielectric layer is situated atop the lead oxide layer and an electron transparent electrode is positioned atop the dielectric layer.
Claim 8
Dependent Claim
22 words
An information storage medium according to claim 5 wherein said transparent electrode is selected from the group consisting of indium and cadmium.
Claim 9
Dependent Claim
90 words
An information storage medium according to claim 5 including voltage biasing means connected between said transparent electrode and said p-type region of said semiconductor wafer, means for selectively impinging an electron beam upon the electron transparent face of said recording medium to effect dielectric breakdown in said medium corresponding to a desired coded pattern and means for locating dielectric breakdown locations in said medium by a measurement of current flow through said semiconductive wafer upon subsequent selective electron beam irradiation of said recording medium with said voltage biasing means removed.
Claim 10
Dependent Claim
18 words
An information storage medium according to claim 6 wherein said dielectric layer is less than 5 mills thick.
Claim 11
Independent Claim
97 words
A method of information storage comprising biasing a structure characterized by a dielectric layer sandwiched between two conductive electrodes to a threshold level below the breakdown level of said dielectric layer, generating an electron beam of sufficient intensity to penetrate through one of said conductive electrodes to said dielectric layer, and selectively causing breakdowns in said dielectric layer by impinging said electron beam upon said transparent electrode in a predetermined coded pattern, said electron beam penetrating into said dielectric layer and effecting a selective breakdown in said dielectric layer at the location of said electron beam penetration.
Claim 12
Independent Claim
97 words
A method of information storage comprising biasing a structure characterized by a dielectric layer sandwiched between two conductive electrodes to a threshold level below the breakdown level of said dielectric layer, generating an electron beam of sufficient intensity to penetrate through one of said conductive electrodes to said dielectric layer, and selectively causing breakdowns in said dielectric layer by impinging said electron beam upon said transparent electrode in a predetermined coded pattern, said electron beam penetrating into said dielectric layer and effecting a selective breakdown in said dielectric layer at the location of said electron beam penetration.
Claim 13
Dependent Claim
45 words
A method of information storage and retrieval according to claim 10 further including removing said threshold bias upon said structure, applying a reverse bias to said structure, and detecting the locations of dielectric breakdown in said structure by selective electron beam interrogation of said structure.
Claim 14
Dependent Claim
52 words
A method of information storage and retrieval according to claim 11 wherein one of said electrodes is a doped semiconductive body and wherein said method further includes the step of detecting said dielectric breakdown by measuring current flow induced in said semiconductive electrode upon selective electron beam irradiation interrogation of said structure.
Claim 15
Independent Claim
124 words
A method of information storage and retrieval comprising biasing a laminar structure having at least one layer characterized by an electrical conductivity variable upon electron irradiation to a threshold value below the voltage breakdown level of said structure, generating an electron beam of sufficient intensity to penEtrate to said one layer, selectively impinging said electron beam upon said variable conductivity layer to selectively exceed the breakdown level of at least one layer of said structure only at the area of electron impingement upon said structure, said breakdown of said layer producing a permanent physical deformation in said layer, removing the threshold bias upon said structure and selectively detecting the locations of said physical breakdown by electron irradiation of said structure without said threshold bias.
Claim 16
Independent Claim
124 words
A method of information storage and retrieval comprising biasing a laminar structure having at least one layer characterized by an electrical conductivity variable upon electron irradiation to a threshold value below the voltage breakdown level of said structure, generating an electron beam of sufficient intensity to penEtrate to said one layer, selectively impinging said electron beam upon said variable conductivity layer to selectively exceed the breakdown level of at least one layer of said structure only at the area of electron impingement upon said structure, said breakdown of said layer producing a permanent physical deformation in said layer, removing the threshold bias upon said structure and selectively detecting the locations of said physical breakdown by electron irradiation of said structure without said threshold bias.
Claim 17
Dependent Claim
58 words
An information storage medium comprising: first and second electrodes spaced relative to one another; a layer of dielectric material and a layer of semiconductive material sandwiched between said electrodes thereby forming a laminar structure; said semiconductive material characterized by an increase in conductivity upon being irradiated by an electron beam causing a permanent deformation in said laminar structure.
Claim 18
Dependent Claim
58 words
An information storage medium comprising: first and second electrodes spaced relative to one another; a layer of dielectric material and a layer of semiconductive material sandwiched between said electrodes thereby forming a laminar structure; said semiconductive material characterized by an increase in conductivity upon being irradiated by an electron beam causing a permanent deformation in said laminar structure.
References Cited (Backward Citations)
US2786880A
Cited
US3445715A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |