Patent US3426422A successfully refreshed from Google Patents.
US3426422A
Expired / Lapsed
US
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Method of making stable semiconductor devices
Assignee: Fairchild Semiconductor Corp
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Filing: 1965-10-23
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Granted: 1969-02-11
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Expires: 1985-10-23
Abstract
No abstract record available.
Inventors
- 👤 Bruce E Deal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:06
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/02; H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10D; H10D30/00; H10D30/60; H10D99/00; H10P14/00; H10P14/60; Y; Y10; Y10S; Y10S148/00; Y10S148/017; Y10S148/043; Y10S438/00; Y10S438/974
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
IN AN IMPROVED METHOD FOR PREPARING SEMICONDUCTOR DEVICES HAVING A SILICON DIOXIDE LAYER BETWEEN AN ALUMINUM LAYER AND A DOPED SILICON SUBSTRATE, THE STEPS OF WHICH MINIMIZE THE INTRODUCTION OF ALKALI METAL IONS INTO THE SILICON DIOXIDE LAYER, WHICH COMPRISES: PRIOR TO THE DEPOSITION OF THE ALUMINUM, REMOVING AT LEAST 10 ANGSTROMS OF THE LAYER OF SILICON DIOXIDE USING AN ALKALI METAL ION-FREE ACID FLUORIDE ETCHANT, VACUUM DEPOSITING PURE ALUMINUM INTO THE SILICON DIOXIDE LAYER, IN THE ESSENTIAL ABSENCE OF ALKALI METAL ION SOURCES, WHEREIN SAID ALUMINUM IS HEATED USING AN ELECTRON BEAM, AND FORMING THE ALUMINUM LAYER INTO THE DESIRED DIMENSIONS USING PHOTORESIST MASSKING TECHNIQUES AND AN ALKALI METAL ION-FREE ETCHANT.
Claim 2
Dependent Claim
112 words
IN AN IMPROVED METHOD FOR PREPARING SEMICONDUCTOR DEVICES HAVING A SILICON DIOXIDE LAYER BETWEEN AN ALUMINUM LAYER AND A DOPED SILICON SUBSTRATE, THE STEPS OF WHICH MINIMIZE THE INTRODUCTION OF ALKALI METAL IONS INTO THE SILICON DIOXIDE LAYER, WHICH COMPRISES: PRIOR TO THE DEPOSITION OF THE ALUMINUM, REMOVING AT LEAST 10 ANGSTROMS OF THE LAYER OF SILICON DIOXIDE USING AN ALKALI METAL ION-FREE ACID FLUORIDE ETCHANT, VACUUM DEPOSITING PURE ALUMINUM INTO THE SILICON DIOXIDE LAYER, IN THE ESSENTIAL ABSENCE OF ALKALI METAL ION SOURCES, WHEREIN SAID ALUMINUM IS HEATED USING AN ELECTRON BEAM, AND FORMING THE ALUMINUM LAYER INTO THE DESIRED DIMENSIONS USING PHOTORESIST MASSKING TECHNIQUES AND AN ALKALI METAL ION-FREE ETCHANT.
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) | 1972-02-11 | 1972-08-12 | 1973-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-02-11 | 1976-08-12 | 1977-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-02-11 | 1980-08-12 | 1981-02-11 | $7700.00 | Window Closed / Lapsed |