US3723199A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Outdiffusion epitaxial self-isolation technique for making monolithicsemiconductor devices
Assignee: International Business Machines Corp
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Filing: 1969-11-10
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Granted: 1973-03-27
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Expires: 1989-11-10
Abstract
Abstract A SUBCOLLECTOR WINDOW IS OPENED IN AN OXIDE COVERED P- SIALICON SUBSTRATE. TWO N DOPANTS OF DIFFERENT DIFFUSION RATES (ARSENIC AND PHOSPHOROUS) ARE DIFFUSED THROUGH THE WINDOW INTO THE SUBSTRATE. THE OXIDE COVERING IS REMOVED AND A P- SILICON EPITAXIAL LAYER IS DEPOSITED ON THE SUBSTRATE AND REOXIDIZED. DURING THE REOXIDATION CYCLE, THE PHSOPHOROUS AND ARSENIC ARE OUT-DIFFUSED, THE PHOSPHORUS REACHING THE TOP SURFACE OF THE EPITAXIAL LAYER TO PRODUCE AN N POCKET IN THE P- EPITAXIAL LAYER AND SUBSTRATE, THE POCKET HAVING A HEAVILY DOPED N+ REGION ADJACENT THE EPITAXIAL LAYER-SUBSTRATE INTERFACE. BASE AND EMITTER DIFFUSIONS ARE MADE WITHIN THE N POCKET TO FORM A TRANSISTOR.
Inventors
- 👤 M Vora
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:43
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/13; H10D62/137; H10D62/138; H10D99/00; H10P; H10P95/00; H10W; H10W15/00; H10W15/01; Y; Y10; Y10S; Y10S148/00; Y10S148/037; Y10S148/049; Y10S148/085; Y10S148/098; Y10S148/145; Y10S148/151; Y10S257/00; Y10S257/919
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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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |