US3760239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coaxial inverted geometry transistor having buried emitter
Assignee: National Aeronautics and Space Administration
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Filing: 1971-06-09
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Granted: 1973-09-18
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Expires: 1991-06-09
Abstract
Abstract The invention relates to an inverted geometry transistor wherein the emitter is buried within the substrate. The transistor can be fabricated as a part of a monolithic integrated circuit and is particularly suited for use in applications where it is desired to employ low actuating voltages. The transistor may employ the same doping levels in the collector and emitter, so these connections can be reversed.
Inventors
- 👤 J Fletcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:31
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10D84/0112; H10D84/02; H10D84/03; H10D84/038; H10D99/00; H10W; H10W10/00; H10W10/01; H10W10/031; H10W10/30; Y; Y10; Y10S; Y10S148/00; Y10S148/037; Y10S148/049; Y10S148/085; Y10S148/151
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
103 words
An improved transistor comprising in combination: a substrate of a semiconductor substance, an epitaxial emitter layer grown on said substrate, said layer being of a first conductivity type, a base layer of a second conductivity type grown as an epitaxial layer on said emitter layer, said base layer having a center arm and a peripheral edge, both extending upwardly and through the top surface of said transistor, a collector of a first conductivity type completely surrounding said arm of the base and extending to said edge of the base, whereby the edge of said base and said collector are coaxial around said arm.
Claim 2
Dependent Claim
103 words
An improved transistor comprising in combination: a substrate of a semiconductor substance, an epitaxial emitter layer grown on said substrate, said layer being of a first conductivity type, a base layer of a second conductivity type grown as an epitaxial layer on said emitter layer, said base layer having a center arm and a peripheral edge, both extending upwardly and through the top surface of said transistor, a collector of a first conductivity type completely surrounding said arm of the base and extending to said edge of the base, whereby the edge of said base and said collector are coaxial around said arm.
Claim 3
Dependent Claim
36 words
The structure of claim 1 wherein said transistor is isolated from other devices on the same substrate by means of a semiconductor material surrounding the emitter and being of the opposite conductivity type from said emitter.
Claim 4
Dependent Claim
26 words
The structure of claim 1 wherein said transistor is isolated from other devices on the same substrate by means of a dielectric layer surrounding the emitter.
Claim 5
Dependent Claim
11 words
The structure of claim 3 wherein said layer is silicon dioxide.
Claim 6
Dependent Claim
33 words
The structure of claim 1 wherein said transistor is isolated from other devices on the same substrate by a gap completely surrounding the edges of the emitter, said gap extending into the substRate.
Claim 7
Dependent Claim
28 words
The structure of claim 1 wherein the peripheral edge of the emitter extends to the top surface of the transistor with an emitter contact on said top surface.
Claim 8
Dependent Claim
18 words
The structure of claim 1 wherein contact is made to the emitter from the bottom of the substrate.
Claim 9
Dependent Claim
32 words
The structure of claim 1 wherein the emitter and the collector are formed by doping the substrate material to the same level whereby the emitter and the collector connections can be reversed.
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) | 1976-09-17 | 1977-03-19 | 1977-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-17 | 1981-03-19 | 1981-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-17 | 1985-03-19 | 1985-09-18 | $7700.00 | Window Closed / Lapsed |