US2740700A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for portraying p-n junctions in silicon
Assignee: AT&T Inc
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Filing: 1954-05-14
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Granted: 1956-04-03
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Expires: 1974-05-14
Abstract
No abstract record available.
Inventors
- 👤 Calvin S Fuller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:04
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
91 words
A METHOD FOR PORTRAYING P-N JUNCTIONS IN A SILICON BODY WHICH COMPRISES THE STEP OF IMMERSING THE SILICON BODY IN AN AQUEOUS STAINING SOLUTION OF HYDROFLUORIC ACID AND NITRIC ACID, THE COMPOSITIN BY WEIGHT OF THE SOLUTION BEING REPRESENTABLE ON A TERNARY COMPOSITION DIAGRAM BY A POINT WITHIN THE AREA ENCOMPASSED BY A QUADRILATERAL HAVING VERTICES APPROXIMATELY AT COORDINATES (97, 1.5, 1.5), (51.4,0.1,48.5), (50.5,1.0,48.5) AND (87, 11, 2.0) WHERE THE FIRST ORDINATE REPRESENTS THE PRECENTAGE CONCENTRATION OF WATER, THE SECOND THAT OF NITRIC ACID, AND THE THIRD THAT OF HYDROFLUORIC ACID.
Claim 2
Independent Claim
91 words
A METHOD FOR PORTRAYING P-N JUNCTIONS IN A SILICON BODY WHICH COMPRISES THE STEP OF IMMERSING THE SILICON BODY IN AN AQUEOUS STAINING SOLUTION OF HYDROFLUORIC ACID AND NITRIC ACID, THE COMPOSITIN BY WEIGHT OF THE SOLUTION BEING REPRESENTABLE ON A TERNARY COMPOSITION DIAGRAM BY A POINT WITHIN THE AREA ENCOMPASSED BY A QUADRILATERAL HAVING VERTICES APPROXIMATELY AT COORDINATES (97, 1.5, 1.5), (51.4,0.1,48.5), (50.5,1.0,48.5) AND (87, 11, 2.0) WHERE THE FIRST ORDINATE REPRESENTS THE PRECENTAGE CONCENTRATION OF WATER, THE SECOND THAT OF NITRIC ACID, AND THE THIRD THAT OF HYDROFLUORIC ACID.
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) | 1959-04-03 | 1959-10-03 | 1960-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-04-03 | 1963-10-03 | 1964-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-04-03 | 1967-10-03 | 1968-04-03 | $7700.00 | Window Closed / Lapsed |