Patent US3220894A successfully refreshed from Google Patents.
US3220894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffused-base transistors, preferably for high-frequency operation
Assignee: Siemens and Halske AG
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Filing: 1963-01-15
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Granted: 1965-11-30
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Expires: 1983-01-15
Abstract
No abstract record available.
Inventors
- 👤 Ruchardt Hugo
- 👤 Hargasser Hans
- 👤 Heissing Hellmuth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:54
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/60; H10D10/00; H10D62/10; H10D99/00; H10P; H10P95/00; H10P95/50; H10W; H10W72/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
93 words
A DIFFUSED-BASE MESA TRANSISTOR, COMPRISING A MONOCRYSTALLINE SEMICONDUCTOR BODY OF GERMANIUM HAVING FOUR REGIONS OF RESPECTIVELY DIFFERENT CONDUCTANCE, ONE OF SAID REGIONS BEING THE COLLECTOR AND FORMING AN ACCEPTOR-DOPED P-TYPE GERMANIUM SLAB OF RELATIVELY LOW OHMIC RESISTANCE AND AT LEAST 100 MICRON THICKNESS, SAID SLAB BEING LARGER THAN THE THREE OTHER REGIONS AND CARRYING SAID OTHER REGIONS, THE SECOND ONE OF SAID REGIONS BEING SO ELITAXIALLY GROWN MESA FOOT PORTION OF SAID SLAB AND FORMING PART OF THE COLLECTOR, SAID EPITAXIAL REGION BEING ACCEPTORDOPED AND HAVING AN OHMIC RESISTANCE OF AT LEAST 10
Claim 2
Dependent Claim
93 words
A DIFFUSED-BASE MESA TRANSISTOR, COMPRISING A MONOCRYSTALLINE SEMICONDUCTOR BODY OF GERMANIUM HAVING FOUR REGIONS OF RESPECTIVELY DIFFERENT CONDUCTANCE, ONE OF SAID REGIONS BEING THE COLLECTOR AND FORMING AN ACCEPTOR-DOPED P-TYPE GERMANIUM SLAB OF RELATIVELY LOW OHMIC RESISTANCE AND AT LEAST 100 MICRON THICKNESS, SAID SLAB BEING LARGER THAN THE THREE OTHER REGIONS AND CARRYING SAID OTHER REGIONS, THE SECOND ONE OF SAID REGIONS BEING SO ELITAXIALLY GROWN MESA FOOT PORTION OF SAID SLAB AND FORMING PART OF THE COLLECTOR, SAID EPITAXIAL REGION BEING ACCEPTORDOPED AND HAVING AN OHMIC RESISTANCE OF AT LEAST 10
References Cited (Backward Citations)
US3006791A
Cited
US3028529A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-11-29 | 1969-05-31 | 1969-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-29 | 1973-05-31 | 1973-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-29 | 1977-05-31 | 1977-11-30 | $7700.00 | Window Closed / Lapsed |