US3569800A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resistively isolated integrated current switch
Assignee: International Business Machines Corp
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Filing: 1968-09-04
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Granted: 1971-03-09
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Expires: 1988-09-04
Abstract
Abstract An integrated circuit is provided in which highly conductive collector current paths within the transistors of a logical current switch are formed by heavily doped buried layers extending into contact with a common base and heavily doped collector plugs extending between the buried layers and the various collector contacts. A lightly doped epitaxial layer surrounds the collector plugs and buried layers to resistively isolate the current switch from external circuit elements and to resistively isolate the collector current paths from one another. The current from the common emitter is crowded through the common base and into selected ones of the collector current paths in accordance with the relative voltages applied to distinct regions of the base electrically separated from one another by a relatively thin central region thereof.
Inventors
- 👤 Thomas W Collins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:32
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/137; H10D99/00; H10W; H10W10/00; H10W10/01; H10W10/031; H10W10/30; H10W15/00; H10W15/01; Y; Y10; Y10S; Y10S148/00; Y10S148/037; Y10S148/085
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
257 words
An integrated circuit comprising a unitary body with a bulk semiconductor material of a first type of semiconductivity forming a substrate region, a plurality of heavily doped regions of a second type of semiconductivity extending into different portions of the substrate region from a surface thereof and forming buried layers, a lightly doped epitaxial layer of material of the second type of semiconductivity extending over said surface of the substrate region and the buried layers, said epitaxial layer having a surface opposite the substrate region which defines the upper surface of the integrated circuit, a plurality of heavily doped regions of the second type of semiconductivity disposed within the epitaxial layer and extending between the upper surface of the integrated circuit and different one of the buried layers to form collector plugs, the expitaxial layer together with the buried layers and the collector plugs forming a collector region, each of the buried layers together with the associated collector plug forming a different collector current path, a base region of material of the first type of semiconductivity extending into the epitaxial layer from the upper surface thereof and having a first portion thereof in contact with each of the buried layers to form a collector-base junction and a plurality of second base portions thereof emanating from the first portion and disposed adjacent different ones of the buried layers, and an emitter region of material of the second typE of semiconductivity extending into the base region and forming an emitter-base junction with the first portion of the base region.
Claim 2
Dependent Claim
257 words
An integrated circuit comprising a unitary body with a bulk semiconductor material of a first type of semiconductivity forming a substrate region, a plurality of heavily doped regions of a second type of semiconductivity extending into different portions of the substrate region from a surface thereof and forming buried layers, a lightly doped epitaxial layer of material of the second type of semiconductivity extending over said surface of the substrate region and the buried layers, said epitaxial layer having a surface opposite the substrate region which defines the upper surface of the integrated circuit, a plurality of heavily doped regions of the second type of semiconductivity disposed within the epitaxial layer and extending between the upper surface of the integrated circuit and different one of the buried layers to form collector plugs, the expitaxial layer together with the buried layers and the collector plugs forming a collector region, each of the buried layers together with the associated collector plug forming a different collector current path, a base region of material of the first type of semiconductivity extending into the epitaxial layer from the upper surface thereof and having a first portion thereof in contact with each of the buried layers to form a collector-base junction and a plurality of second base portions thereof emanating from the first portion and disposed adjacent different ones of the buried layers, and an emitter region of material of the second typE of semiconductivity extending into the base region and forming an emitter-base junction with the first portion of the base region.
Claim 3
Dependent Claim
22 words
An integrated circuit in accordance with claim 1, wherein the emitter region is heavily doped and the base region is lightly doped.
Claim 4
Dependent Claim
166 words
An integrated current switch comprising an emitter element of semiconductor material of a first conductivity type, an emitter contact mounted on the emitter element, a base element of semiconductor material of a second conductivity type opposite the first conductivity type having a central portion thereof in contact with the emitter element to form an emitter-base junction and four outer portions thereof substantially symmetrically emanating from the central portion, four base contacts mounted on respective ones of the four outer portions of the base element, a collector element of semiconductor material of the first conductivity type having a pair of highly conductive portions thereof, one of which is in contact with the central portion of the base element and three of the four outer portions and the other of which is in contact with the central portion of the base element and the fourth outer portion, and a pair of collector contacts mounted on different ones of the pair of highly conductive portions of the collector element.
Claim 5
Dependent Claim
166 words
An integrated current switch comprising an emitter element of semiconductor material of a first conductivity type, an emitter contact mounted on the emitter element, a base element of semiconductor material of a second conductivity type opposite the first conductivity type having a central portion thereof in contact with the emitter element to form an emitter-base junction and four outer portions thereof substantially symmetrically emanating from the central portion, four base contacts mounted on respective ones of the four outer portions of the base element, a collector element of semiconductor material of the first conductivity type having a pair of highly conductive portions thereof, one of which is in contact with the central portion of the base element and three of the four outer portions and the other of which is in contact with the central portion of the base element and the fourth outer portion, and a pair of collector contacts mounted on different ones of the pair of highly conductive portions of the collector element.
Claim 6
Dependent Claim
71 words
An integrated current switch in accordance with claim 3, wherein each of the pair of highly conductive portions of the collector element comprises a heavily doped buried layer in contact with the central portion of the base element and a heavily doped column extending between the buried layer and one of the pair of collector contacts, and the collector element includes a substantially nonconductive portion surrounding the buried layers and columns.
Claim 7
Dependent Claim
135 words
An integrated circuit comprising a body of semiconductor material having a major surface and including an emitter region of one conductivity type, a base region of opposite conductivity type from the one conductivity type surrounding the emitter region and forming an emitter-base junction therewith, and a collector region of the one conductivity type extending into the semiconductor material from the major surface and surrounding the base region to form a collector-base junction therewith, the collector region being intrinsically doped and including a plurality of degenerately doped portions thereof extending between the base region and separate portions of the major surface to form a plurality of collector current paths, the intrinsically doped collector region resistively isolating the degenerately doped portions from one another and resistively isolating the emitter, base and collector regions within the integrated circuit.
Claim 8
Dependent Claim
135 words
An integrated circuit comprising a body of semiconductor material having a major surface and including an emitter region of one conductivity type, a base region of opposite conductivity type from the one conductivity type surrounding the emitter region and forming an emitter-base junction therewith, and a collector region of the one conductivity type extending into the semiconductor material from the major surface and surrounding the base region to form a collector-base junction therewith, the collector region being intrinsically doped and including a plurality of degenerately doped portions thereof extending between the base region and separate portions of the major surface to form a plurality of collector current paths, the intrinsically doped collector region resistively isolating the degenerately doped portions from one another and resistively isolating the emitter, base and collector regions within the integrated circuit.
Claim 9
Dependent Claim
46 words
An integrated circuit in accordance with claim 5, wherein each of the degenerately doped portions comprises a buried layer disposed in contact with the base region and a column extending from one of the separate portions of the major surface into contact with the buried layer.
Claim 10
Dependent Claim
18 words
An integrated circuit in accordance with claim 6, wherein the collector region comprises an intrinsically doped epitaxial layer.
Claim 11
Dependent Claim
62 words
An integrated circuit in accordance with claim 6, wherein the base region includes a central portion thereof extending between the emitter and collector regions and a plurality of distinct outer portions extending between the central portion and separate portions of the major surface, each of the distinct outer portions in combination with the central portion defining the base of a separate transistor.
Claim 12
Dependent Claim
73 words
An integrated circuit in accordance with claim 8, wherein the emitter region is degenerately doped and the central portion of the base region is intrinsically doped, whereby current within the emitter region is crowded through the central portion of the base region and into a selected one of the degenerately doped portions of the collector region in accordance with the relative values of voltages at the distinct outer portions of the base region.
Claim 13
Dependent Claim
76 words
An integrated circuit in acCordance with claim 9, further including an emitter contact disposed on the emitter region at the major surface, a plurality of base contacts, each of which is disposed on a different one of the distinct outer portions of the base region at the major surface, and a plurality of collector contacts, each of which is disposed on the column of a different one of the degenerately doped portions at the major surface.
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) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |