US3916431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bipolar integrated circuit transistor with lightly doped subcollector core
Assignee: RCA Corp
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Filing: 1974-06-21
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Granted: 1975-10-28
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Expires: 1994-06-21
Abstract
Abstract Crystal dislocations, in that portion of an epitaxial layer of semiconductive material over a buried pocket in a substrate in which a bipolar transistor''s emitter is located, are reduced by providing the buried pocket with a lower concentration of conductivity modifiers under the emitter.
Inventors
- 👤 Heshmat Khajezadeh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:05
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/137; Y; Y10; Y10S; Y10S148/00; Y10S148/007; Y10S148/037; Y10S148/085; Y10S148/145
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
183 words
IM AN INTEGRATED CIRCUIT DEVICE OF THE TYPE WHICH HAS A SUBSTRATE OF ONE TYPE CONDUCTIVITY, A LAYERLIKE BODY OF SEMICONDUCTIVE MATERIAL OF OPPOSITE TYPE CONDUCTIVITY ON SAID SUBSTRATE AND HAVING A SURFACE, THERE BEING A SUBSTANTIALLY PLANAR INTERFACE BETWEEN SAID SUBSTRATE OF SAID LAYERLIKE BODY, MEANS IN SAID LAYER-LIKE BODY DEFINING A BIPOLAR TRASISTOR, SAID MEANS COMPRISING A BASE REGION OF SAID ONE TYPE CONDUCTIVITY IN SAID LAYERLIKE BODY, AN EMITTER REGION OF SAID OPPOSITE TYPE CONDUCTIVITY IN SAID BASE REGION AND HAVING A PREDETERMINE AREA AND CONFIGURATION IN THE PLANE OF SAID SURFACE, AND A POCKET REGION OF SAID OPPOSITE TYPE CONDUCTIVITY IN SAID SUBSTRATE DISPOSED OPPOSITE TO ALL THE AREA OF SAID EMITTER REGION BENEATH SAID INTERFACE AND EXTENDING BEYOND THE AREA OF SAID EMITTER REGION, THE IMPROVEMENT WHEREIN THE DENSITY OF CONDUCTIVITY MODIFIERS IN A SUBSTANTIAL PORTION OF THAT PART OF SAID POCKER REGION WHICH IS DISPOSED OPPOSITE THE CENTRAL AREA OF SAID EMITTER REGION IS LESS THAN THE DENSITY OF CONDUCTIVITY MODIFIERS IN PARTS OF SAID POCKET REGION DISPOSED OPPISITE THE OUTER PERIPHDRAL AREA OF SAID EMITTER REGION.
Claim 2
Dependent Claim
183 words
IM AN INTEGRATED CIRCUIT DEVICE OF THE TYPE WHICH HAS A SUBSTRATE OF ONE TYPE CONDUCTIVITY, A LAYERLIKE BODY OF SEMICONDUCTIVE MATERIAL OF OPPOSITE TYPE CONDUCTIVITY ON SAID SUBSTRATE AND HAVING A SURFACE, THERE BEING A SUBSTANTIALLY PLANAR INTERFACE BETWEEN SAID SUBSTRATE OF SAID LAYERLIKE BODY, MEANS IN SAID LAYER-LIKE BODY DEFINING A BIPOLAR TRASISTOR, SAID MEANS COMPRISING A BASE REGION OF SAID ONE TYPE CONDUCTIVITY IN SAID LAYERLIKE BODY, AN EMITTER REGION OF SAID OPPOSITE TYPE CONDUCTIVITY IN SAID BASE REGION AND HAVING A PREDETERMINE AREA AND CONFIGURATION IN THE PLANE OF SAID SURFACE, AND A POCKET REGION OF SAID OPPOSITE TYPE CONDUCTIVITY IN SAID SUBSTRATE DISPOSED OPPOSITE TO ALL THE AREA OF SAID EMITTER REGION BENEATH SAID INTERFACE AND EXTENDING BEYOND THE AREA OF SAID EMITTER REGION, THE IMPROVEMENT WHEREIN THE DENSITY OF CONDUCTIVITY MODIFIERS IN A SUBSTANTIAL PORTION OF THAT PART OF SAID POCKER REGION WHICH IS DISPOSED OPPOSITE THE CENTRAL AREA OF SAID EMITTER REGION IS LESS THAN THE DENSITY OF CONDUCTIVITY MODIFIERS IN PARTS OF SAID POCKET REGION DISPOSED OPPISITE THE OUTER PERIPHDRAL AREA OF SAID EMITTER REGION.
Claim 3
Dependent Claim
53 words
An integrated circuit device as defined in claim 1, wherein the density of conductivity modifiers in that part of said pocket region opposite the central area of the emitter region decreases as a function of distance parallel to said surface from the outer peripheral area of said emitter region toward the center thereof.
Claim 4
Dependent Claim
17 words
An integrated circuit device as defined in claim 2, wherein said one type conductivity is P type.
Claim 5
Dependent Claim
116 words
An integrated circuit device comprising: a substrate of semiconductive material of one type conductivity, an epitaxial layer of semiconductive material of opposite type conductivity on said substrate, means in said epitaxial layer defining a bipolar transistor including emitter, base, and collector regions, and a pocket region of said opposite type conductivity adjacent to the interface between said substrate and said layer, said pocket region having a portion thereof disposed within said substrate beneath said emitter region, the density of conductivity modifiers in said portion of said pocket region decreasing from a relatively high value beneath the outer peripheral areas of said emitter region to a relatively low value beneath the central area of said emitter region.
Claim 6
Dependent Claim
116 words
An integrated circuit device comprising: a substrate of semiconductive material of one type conductivity, an epitaxial layer of semiconductive material of opposite type conductivity on said substrate, means in said epitaxial layer defining a bipolar transistor including emitter, base, and collector regions, and a pocket region of said opposite type conductivity adjacent to the interface between said substrate and said layer, said pocket region having a portion thereof disposed within said substrate beneath said emitter region, the density of conductivity modifiers in said portion of said pocket region decreasing from a relatively high value beneath the outer peripheral areas of said emitter region to a relatively low value beneath the central area of said emitter region.
Claim 7
Dependent Claim
16 words
An integrated circuit device as defined in claim 4, wherein said semiconductive material is monocrystalline silicon.
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) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |