US3666573A
Expired / Lapsed
US
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Method for making transistors including gain determining step
Assignee: RCA Corp
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Filing: 1969-12-17
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Granted: 1972-05-30
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Expires: 1989-12-17
Abstract
Abstract THE METHOD INCLUDES PROVIDING A UNIFORMLY THICK BASE LAYER ON A WAFER OF SEMICONDUCTOR MATERIAL WHICH IS TO BECOME TRANSISTOR COLLECTORS, AND DIFFUSING A PLURALITY OF SEPARATE EMITTER REGIONS INTO THE BASE LAYER. DURING EMITTER DIFFUSION, A GRID OF LIKE CONDUCTIVITY IS DIFFUSED INTO THE BASE LAYER AND BETWEEN ADJACENT EMITTER REGIONS TO ISOLATE THE ACTIVE REGION OF EACH TRANSITOR. A GAIN FIGURE-OF-MERIT IS THEN MEASURED FOR ONE TRANSISTOR IN THE WAFER, AND IF BELOW A DESIRED MINIMUM, THE EMITTER REGIONS ARE REDIFFUSED. AFTER ACHIEVEING THE DESIRED GAIN, THE TRANSISTORS ARE SEPARATED FROM THE WAFER.
Inventors
- 👤 Norbert William Brackelmanns
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:24
CPC Classifications
H; H10; H10P; H10P95/00; G; G01; G01R; G01R31/00; G01R31/26; G01R31/2607; G01R31/2608; G01R31/2614; H10D; H10D99/00; H10P54/00; H10P74/00; H10P74/23; Y; Y10; Y10S; Y10S148/00; Y10S148/085; Y10S148/162
Claims Analysis
Total Claims: 0
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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) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |