Patent US3667004A successfully refreshed from Google Patents.
US3667004A
Expired / Lapsed
US
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Electroluminescent semiconductor display apparatus
Assignee: AT&T Inc
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Filing: 1970-10-26
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Granted: 1972-05-30
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Expires: 1990-10-26
Abstract
Abstract An electroluminescent semiconductor display comprises a plurality of electroluminescent semiconductor devices, which are electrically connected together in a rectangular random access type of beam lead array. Each electroluminescent device includes an N-type gallium phosphide semiconductor base member of one conductivity type having a mesa in which a P-N junction is located. A beam lead array parallel to the x direction contacts the P-type zone through apertures in a light reflecting coating on the plateau surface of each of the mesas, whereas a beam lead array parallel to the y direction contacts each of the N-type base regions in two separate portions thereof, thereby avoiding the need for any leads which are in the path of the emitted light. The shape and conductivity profile of the N-type zones in the base region and the plateau are tailored in order to serve as efficient electrical crossover conductors for the beam leads in the y direction as well as to reduce light absorption.
Inventors
- 👤 Matthew Kuhn
- 👤 Norman Edwin Schumaker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:58
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/60; H10H; H10H20/00; H10H20/80
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
209 words
An electroluminescent device, amenable for connection into an array to provide a display, comprising: a. a semiconductive crystal including a base portion and a continuous mesa portion extending from the base portion, the mesa portion including first and second zones respectively of first and second conductivity types defining a P-N junction therebetween, the first zone including a major surface of the mesa; b. an apertured reflective dielectric layer extending over the major surface of the mesa, said layer having a plurality of apertures through each of which the first zone of the mesa can be electrically contacted by an electrode; c. a conductive coating extending over said dielectric layer and contacting electrically the first zone of the mesa at each of the apertures in said layer; d. a pair of spaced apart electrical terminals oppositely connected to said coating; and e. a pair of spaced apart electrical terminals contacting the base at separate locations, the base including both a first region of low electrical conductivity of a second type, and a second region including said separate locations at its boundary and having high electrical conductivity of the same conductivity type as said second zone, said second region extending in the base from both said locations to the second zone.
Claim 2
Dependent Claim
209 words
An electroluminescent device, amenable for connection into an array to provide a display, comprising: a. a semiconductive crystal including a base portion and a continuous mesa portion extending from the base portion, the mesa portion including first and second zones respectively of first and second conductivity types defining a P-N junction therebetween, the first zone including a major surface of the mesa; b. an apertured reflective dielectric layer extending over the major surface of the mesa, said layer having a plurality of apertures through each of which the first zone of the mesa can be electrically contacted by an electrode; c. a conductive coating extending over said dielectric layer and contacting electrically the first zone of the mesa at each of the apertures in said layer; d. a pair of spaced apart electrical terminals oppositely connected to said coating; and e. a pair of spaced apart electrical terminals contacting the base at separate locations, the base including both a first region of low electrical conductivity of a second type, and a second region including said separate locations at its boundary and having high electrical conductivity of the same conductivity type as said second zone, said second region extending in the base from both said locations to the second zone.
Claim 3
Dependent Claim
51 words
A device in accordance with claim 1 in which the conductive coating over the insulating layer and the two electrical terminals connected thereto form an integral beam lead, and in which the total area of the apertures is less than one-third of the area of the major surface of the mesa.
Claim 4
Dependent Claim
49 words
A device in accordance with claim 1 in which the P-N junction forms a surface which is essentially parallel to the major surface of the mesa, and in which a portion of the dielectric layer extends over the intersection of the P-N junction with the sides of the mesa.
Claim 5
Dependent Claim
19 words
The device of claim 1 in which the semiconductor of the base and the mesa is essentially gallium phosphide.
Claim 6
Dependent Claim
33 words
The device of claim 4 in which the Second region and the second zone are both essentially N-type gallium phosphide which has been epitaxially grown on an exposed surface of the first region.
Claim 7
Dependent Claim
22 words
The device of claim 3 in which the first zone is epitaxially grown upon a major exposed surface of the second zone.
Claim 8
Dependent Claim
16 words
The device of claim 6 in which the first and second zones are both gallium phosphide.
Claim 9
Dependent Claim
14 words
The device of claim 7 in which the second zone is N-type gallium phosphide.
Claim 10
Dependent Claim
58 words
The device of claim 8 in which the first region has a net significant donor impurity concentration in the range of less than about 2 X 1017 per cm3, and the second region and the second zone have a net significant donor impurity concentration in the range of about 5 X 1017 to 15 X 1017 per cm3.
Claim 11
Dependent Claim
28 words
The device of claim 9 in which the first zone has a net significant acceptor impurity concentration of about 2 X 1017 to 7 X 1017 per cm3.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |