US2879190A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fabrication of silicon devices
Assignee: AT&T Inc
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Filing: 1957-03-22
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Granted: 1959-03-24
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Expires: 1977-03-22
Abstract
No abstract record available.
Inventors
- 👤 Ralph A Logan
- 👤 Arthur J Peters
- 👤 Tanenbaum Morris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:22
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; C; C30; C30B; C30B31/00; C30B31/06; H10D10/00; H10P; H10P10/00; H10P95/00; Y; Y10; Y10S; Y10S438/00; Y10S438/914; Y10S438/919; Y10S438/92
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
103 words
THE PROCESS OF FORMING A SILICON P-N-P TRANSISTOR COMPRISING THE STEPS OF HEATING A P-TYPE SILICON CRYSTAL FOR AT LEAST AN HOUR AT A TEMPERATURE BETWEEN 1000*C. AND 1400*C. IN AN AMBIENT WHICH INCLUDES OXYGEN AND BORON FOR FORMING IN THE CRYSTAL A BORON-RICH SURFACE LAYER AND AN OXYGEN-RICH REGION INTERMEDIATE BETWEEN SAID SURFACE LAYER AND THE P-TYPE BULK, HEATING THE CRYSTAL FOR AT LEAST HALF AN HOUR AT A TEMPERATURE BETWEEN 300*C. AND 500*C. FOR CONVERTING THE OXYGEN-RICH REREGION TO N-TYPE, AND MAKING SEPARATE LOW RESISTANCE CONNECTIONS TO THE BORON-RICH SURFACE LAYER, THE N-TYPE REGION AND THE P-TYPE BULK OF THE CRYSTAL.
Claim 2
Dependent Claim
103 words
THE PROCESS OF FORMING A SILICON P-N-P TRANSISTOR COMPRISING THE STEPS OF HEATING A P-TYPE SILICON CRYSTAL FOR AT LEAST AN HOUR AT A TEMPERATURE BETWEEN 1000*C. AND 1400*C. IN AN AMBIENT WHICH INCLUDES OXYGEN AND BORON FOR FORMING IN THE CRYSTAL A BORON-RICH SURFACE LAYER AND AN OXYGEN-RICH REGION INTERMEDIATE BETWEEN SAID SURFACE LAYER AND THE P-TYPE BULK, HEATING THE CRYSTAL FOR AT LEAST HALF AN HOUR AT A TEMPERATURE BETWEEN 300*C. AND 500*C. FOR CONVERTING THE OXYGEN-RICH REREGION TO N-TYPE, AND MAKING SEPARATE LOW RESISTANCE CONNECTIONS TO THE BORON-RICH SURFACE LAYER, THE N-TYPE REGION AND THE P-TYPE BULK OF THE CRYSTAL.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-03-23 | 1962-09-22 | 1963-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-03-23 | 1966-09-22 | 1967-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-03-23 | 1970-09-22 | 1971-03-24 | $7700.00 | Window Closed / Lapsed |