US3752715A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of high speed complementary transistors
Assignee: International Business Machines Corp
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Filing: 1971-11-15
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Granted: 1973-08-14
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Expires: 1991-11-15
Abstract
Abstract COMPLEMENTARY NPN AND PNP TRANSISTORS ARE PREPARED SIMULTANEOUSLY WHICH HAVE PROPERTIES OF A HIGH FREQUENCY RESPONSE. SELECTED IMPURITY CONCENTRATIONS ARE EMPLOYED WHEREBY THE SECOND EMITTER DIFFUSION IS PERFORMED WITH THE FIRST EMITTER AREA UNMASKET. THIS ELIMINATES AND EMITTER CONTACT OPENING STEP SUCH THAT EACH CONTACT AREA AND EMITTER ARE CO-EXTENSIVE. OTHER CIRCUIT COMPONENTS SUCH AS RESISTORS AND DIODES ARE ALSO FORMED DURING THE FORMATION OF THE NPN AND PNP TRANSISTORS.
Inventors
- 👤 I Antipov
- 👤 A Oberai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:37
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10D84/0112; H10D84/0119; H10D84/0121; H10D84/02; H10D84/03; H10D84/038; H10D84/60; H10D84/67; H10D84/673; Y; Y10; Y10S; Y10S148/00; Y10S148/037; Y10S148/053; Y10S148/085; Y10S148/151
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |