US2802760A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oxidation of semiconductive surfaces for controlled diffusion
Assignee: AT&T Inc
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Filing: 1955-12-02
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Granted: 1957-08-13
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Expires: 1975-12-02
Abstract
No abstract record available.
Inventors
- 👤 Derick Lincoln
- 👤 Carl J Frosch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:02
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/45; C04B41/52; H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10P14/6322; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/036; Y10S148/037; Y10S148/043; Y10S148/049; Y10S148/118; Y10S148/144; Y10S148/151; Y10S438/00; Y10S438/914; Y10S438/92; Y10S438/923
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
155 words
THE PROCESS OF TREATING A SEMICONDUCTIVE SILICON WAFER WHICH COMPRISES THE STEPS OF HEATING THE WAFER TO BETWEEN 1100*C AND 1400*C. IN AN OXIDIZING ATMOSPHERE WHICH INCLUDES WATER VAPOR FOR AT LEAST TEN MINUTES TO FORM A SURFACE OXIDE FILM THEREOVER WHICH IS BETWEEN 1500 AND 3500 ANGSTROMS THICK, REMOVING THE SURFACE OXIDE FILM FROM PORTIONS OF THE WAFER, REHEATING THE WAFER TO BETWEEN 1100*C.AND 1400*C. IN AN ATMOSPHERE INCLUDING WATER VAPOR AND THE VAPOR OF A CONDUCTIVITY-TYPE DETERMINING IMPURITY WHICH WILL DIFFUSE DIFFERENTIALLY IN REGIONS OF THE SILICON BODY UNDERLYLING PORTIONS WHERE THE SURFACE OXIDE FILM WAS REMOVED AND IN REGIONS OF THE SILICON WAFER UNDERLYING PORTIONS WHERE THE SURFACE OXIDE FILM WAS NOT REMOVED AND REHEATING THE WAFER TO BETWEEN 1100*C. AND 1400*C. IN AN OXIDIZING ATMOSPHERE INCLUDING WATER VAPOR AND THE VAPOR OF A CONDUCTIVITY-TYPE DETERMINING IMPURITY OF THE TYPE OPPOSITE TO THE LAST-MENTIONED CONDUCTIVITY-TYPE DETERMINING IMPURITY FOR DIFFUSION INTO THE BODY.
Claim 2
Dependent Claim
155 words
THE PROCESS OF TREATING A SEMICONDUCTIVE SILICON WAFER WHICH COMPRISES THE STEPS OF HEATING THE WAFER TO BETWEEN 1100*C AND 1400*C. IN AN OXIDIZING ATMOSPHERE WHICH INCLUDES WATER VAPOR FOR AT LEAST TEN MINUTES TO FORM A SURFACE OXIDE FILM THEREOVER WHICH IS BETWEEN 1500 AND 3500 ANGSTROMS THICK, REMOVING THE SURFACE OXIDE FILM FROM PORTIONS OF THE WAFER, REHEATING THE WAFER TO BETWEEN 1100*C.AND 1400*C. IN AN ATMOSPHERE INCLUDING WATER VAPOR AND THE VAPOR OF A CONDUCTIVITY-TYPE DETERMINING IMPURITY WHICH WILL DIFFUSE DIFFERENTIALLY IN REGIONS OF THE SILICON BODY UNDERLYLING PORTIONS WHERE THE SURFACE OXIDE FILM WAS REMOVED AND IN REGIONS OF THE SILICON WAFER UNDERLYING PORTIONS WHERE THE SURFACE OXIDE FILM WAS NOT REMOVED AND REHEATING THE WAFER TO BETWEEN 1100*C. AND 1400*C. IN AN OXIDIZING ATMOSPHERE INCLUDING WATER VAPOR AND THE VAPOR OF A CONDUCTIVITY-TYPE DETERMINING IMPURITY OF THE TYPE OPPOSITE TO THE LAST-MENTIONED CONDUCTIVITY-TYPE DETERMINING IMPURITY FOR DIFFUSION INTO THE BODY.
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) | 1960-08-12 | 1961-02-11 | 1961-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-08-12 | 1965-02-11 | 1965-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-08-12 | 1969-02-11 | 1969-08-13 | $7700.00 | Window Closed / Lapsed |