US3714526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phototransistor
Assignee: National Aeronautics and Space Administration
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Filing: 1971-02-19
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Granted: 1973-01-30
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Expires: 1991-02-19
Abstract
Abstract The invention described herein was made in the performance of work under a NASA Contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 U.S.C. 2457). A phototransistor in which there is included as a part of its integral structure an auxiliary diode in the form of an added base-collector junction which is formed in the surface of the base element and thus out of the direct path between the emitter and collector regions of the phototransistor.
Inventors
- 👤 G Low
- 👤 Cann D Mc
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:33
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/24; H10F30/245; H10F99/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
185 words
A phototransistor comprising: a collector element comprising a semiconductor region of a first conductivity type material; a base element comprising a semiconductor substrate of a second and opposite conductivity type material integrally formed in a surface of said collector element: an emitter element comprising a semiconductor substrate of said first conductivity type material formed in a portion of the surface of said base element and providing an exposed surface adapted to receive a light flux; an auxiliary collector element comprising a semiconductor of said first conductivity type of higher concentration than said collector element, said auxiliary element diffused in the principal portion of the otherwise free surface of said base element and said auxiliary element extending into contact with said collector element; whereby the effective base-collector junction is extended by a configuration wherein a substantial region of the base of the phototransistor is sandwiched between effective collector regions providing an effective extension of the base-collector regions remote from the path between the emitter and collector of the phototransistor and thereby substantially increasing the collector-base junction capacitance without making the phototransistor more susceptible to emitter-collector breakdown.
Claim 2
Dependent Claim
185 words
A phototransistor comprising: a collector element comprising a semiconductor region of a first conductivity type material; a base element comprising a semiconductor substrate of a second and opposite conductivity type material integrally formed in a surface of said collector element: an emitter element comprising a semiconductor substrate of said first conductivity type material formed in a portion of the surface of said base element and providing an exposed surface adapted to receive a light flux; an auxiliary collector element comprising a semiconductor of said first conductivity type of higher concentration than said collector element, said auxiliary element diffused in the principal portion of the otherwise free surface of said base element and said auxiliary element extending into contact with said collector element; whereby the effective base-collector junction is extended by a configuration wherein a substantial region of the base of the phototransistor is sandwiched between effective collector regions providing an effective extension of the base-collector regions remote from the path between the emitter and collector of the phototransistor and thereby substantially increasing the collector-base junction capacitance without making the phototransistor more susceptible to emitter-collector breakdown.
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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |