Patent US654884A successfully refreshed from Google Patents.
US3574009A
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Controlled doping of semiconductors
Assignee: Unitrode Corp
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Filing: 1968-03-06
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Granted: 1971-04-06
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Expires: 1988-03-06
Abstract
Abstract A METHOD FOR CONTROLLABLY DOPING A SEMICONDUCTOR BODY IN WHICH ONLY TIME AND TEMPERATURE ARE THE PROCESS PARMETERS CONTROLLED TO ACHIEVE INTENDED DOPING PROFILES. A CONCENTRATION OF DOPANT DETERMINED ONLY BY TEMPERATURE IS FORMED ON A SEMICONDUCTOR SURFACE TO ACT AS A SOURCE LAYER FOR SUBSEQUENT DIFFUSION. A SELECTED AMOUNT OF DOPANT FROM THIS SOURCE LAYER IS DRIVEN INTO THE SEMICONDUCTOR AND, AFTER DRIVE-IN OF THE SELECTED AMOUNT, FURTHER DRIVE-IN OF DOPANT IS PREVENTED. THIS SELECTED AMOUNT OF DOPANTS IS THEN DIFFUSED INTO THE SEMICONDUCTOR TO ACHIEVE THE DESIRED UMPURITY CONCENTRATION AND DEPTH.
Inventors
- 👤 George Chizinsky
- 👤 Beverly Farms
- 👤 Edward Simon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:57
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/141; H10P32/17; H10P32/171; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/015; Y10S148/049; Y10S148/051; Y10S148/085; Y10S148/144; Y10S148/145; Y10S438/00; Y10S438/914; Y10S438/92
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |